Tinea Pedis in Children Anne
McBride, MD, Bernard A. Cohen,
\s=b\ Objective.\p=m-\Todemonstrate that tinea
pedis should be considered in the differential diagnosis of children with foot dermatitis. Design. \p=m-\Patient series. Setting.\p=m-\Outpatientdermatology practice at the Children's Hospital of Pittsburgh (Pa). Participants.\p=m-\Children with culture-proven tinea pedis from 1987 until 1990. Measurements/Main Results. \p=m-\Fungal cultures were used to identify 13 girls and 13 boys ranging in age from 17 months to 18 years with tinea pedis. A parent was the probable source of infection in at least 25% of cases. Conclusions.\p=m-\Tineapedis is not a rare occurrence in children and should be considered in any patient with a foot rash. (AJDC. 1992;146:844-847)
accepted that tinea pedis "athlete's foot" in children.1"3 Moreover, only few anecdotal It isisgenerally and small series of children with tinea or
rare
a
pedis are re¬ ported in the literature.4-5 During the past several years, cases
have treated numerous children with this infection, and we routinely consider this diagnosis in the evaluation of prepubertal children with foot dermatitis. The goal of this study was to document the problem of tinea pedis in the pediatrie age group. We describe our experience with 26 patients to support our clinical im¬ pression that this disorder occurs regularly in children. we
MATERIALS AND METHODS We reviewed the medical records of all patients with tinea pe¬ dis and a positive fungal culture seen in the Pediatrie Dermatol¬ ogy Clinic at the Children's Hospital of Pittsburgh (Pa) from 1987 until 1990. Cases were identified from a diagnostic registry maintained in the hospital clinic area. Patients with a positive potassium hydroxide (KOH) preparation but no record of a fun¬ gal culture were not included in the study. Fungal cultures were obtained by brushing scale and nail shavings directly onto a modified Sabouraud's dextrose agar plate. Cultures were then transported to the microbiology labo¬ ratory at the hospital and maintained at 30°C for 4 weeks. Fungi
Accepted for publication January 27, 1992. From the Department of Dermatology, University of Pittsburgh (Pa) School of Medicine (Dr McBride), and the Departments of Pediatrics and Dermatology, The Johns Hopkins University School of Medicine, Baltimore, Md (Dr Cohen). Reprint requests to Division of Pediatric Dermatology, Johns Hopkins Medical Institutions, 600 N Wolfe St, CMSC 2-116, Baltimore, MD 21205-2104
(Dr Cohen).
MD
identified by specific colony morphologic characteristics microscopic examination. Medical records were reviewed for biographical and historical data, including age at diagnosis, sex, duration of symptoms, physical findings at examination, KOH preparation results, cul¬ ture results, treatment regimen, and family history of tinea pedis. were
and
RESULTS of Twenty-six culture-proven tinea pedis were identified from 1987 until 1990 (Table). This included 13 boys and 13 girls ranging in age from 17 months to 18 years (median age, 7 years). Two children were younger than age 2 years, and 20 (77%) were white. All patients were otherwise healthy. None was taking immunosup¬ pressive agents at the time of consultation. The most common presenting complaint was a scaly, pruritic, erythematous eruption on the plantar and dorsal surfaces of the feet, with maceration in the lateral toe web spaces (Figs 1 through 3). Vesicles were noted in 16% of the patients (n 4). Duration of symptoms ranged from 2 weeks to 12 years (mean, 6 months). Documentation of KOH preparation was recorded in only 50% of the cases. Of these 13 cases, only one was cases
=
positive.
Thirteen of 26 patients, or their parents, were ques¬ tioned about a family history of tinea pedis. Sixty-nine percent (nine of 13) of these patients had a family history of tinea pedis, and the most commonly affected contact was a
parent.
COMMENT Foot dermatitis is a frequent problem in children. Tinea pedis must be differentiated from a number of other dis¬ orders that also produce inflammatory lesions on the feet. Tinea pedis is most commonly confused with eczema or atopic dermatitis. Eczema is characterized by erythema, scaling, and occasionally vesiculation on the palmar and plantar surfaces as well as the top of the hands and feet, particularly over bony prominences and flexures. Chronic disease is associated with lichenification, pigmentary changes, painful Assuring, and a high risk of secondary bacterial infection. Dyshidrosis, a clinical variant of atopic dermatitis, is characterized by intensely pruritic deepseated vesicles on the palms, soles, and sides of the dig¬ its. In eczema, the eruption is symmetric and KOH prep¬ arations and cultures for fungus are negative. A positive personal and family history of atopy and atopic dermati-
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Biographical and Case Noy
Duration of
Age/Sex
Symptoms
1/16
y/M
2/18 mo/M
Physical Findings at
Potassium
Examination
1y
Dystrophie great toenails
3
Blisters
mo
on
Historical Data
feet and between
Culture Result
Hydroxide Preparation
Trichophyton
No data
rubrum
Econazole nitrate twice daily
No data
T rubrum
Naftifine
Father
hydrochloride twice daily
toes
3/3
4/4
5/6
y/M
2 wk
y/F
9
mo
y/M
8 6
y/F 8/7 y/F 9/5 y/F
rubrum
No data
Blisters
on
rubrum
feet
No data
Maceration between toes and onychomycosis
rubrum
mo
Maceration between toes and onychomycosis
rubrum
mo
Blisters and
erythema
No data
y/F
11/15
y/F
-
Negative
+
Clotrimazole
No data
+
rubrum
Griseofulvin
Father
No data
Miconazole nitrate
No data
No data
Fine scale on soles of feet and maceration between
rubrum
Clotrimazole twice
No data
-
3
mo
No data
Onychomycosis
daily, griseofulvin rubrum
Scales and erythema on plantar surface of right foot
13/12
y/M
12 y
y/M
6
Dry, scaly feet
mo
3y
No data
Clotrimazole twice
No data
Trichophyton
None
No data
mentagro-
-
phytes
rubrum
mentagro-
No data
None
No data
+
No data
Clotrimazole twice
No data
-
Clotrimazole twice
No data
daily
phytes
rubrum
daily
Maceration between toes
rubrum
-
Clotrimazole twice
Father
daily y/F
17/13 18/10 19/11
-
3
mo
Fine scale and
rubrum
None
No data
y/M
2
mo
Maceration between toes and onychomycosis
rubrum
Clotrimazole twice
Father/ brother
y/M
5y
Maceration between toes
rubrum
Clotrimazole twice
Father
y/M
6y
erythema on plantar surface of feet
daily daily
Blisters between toes
rubrum
21/9
y/M y/M
22/17 mo/F
No data 3 mo
4 mo
Erythema and
scales soles of feet
on
rubrum
Clotrimazole twice No data
Econazole nitrate twice
Erythema and
scales on soles of feet and maceration between toes
Maceration between toes
rubrum
No data
rubrum
No data
y/M
24/18
25/10 26/8
y/F y/F
y/F
Erythema and scales
3 y
No data
3y 15
on
rubrum
soles of feet with fissures
Onychomycosis Erythema and scales on
rubrum
No data
rubrum
daily
Econazole nitrate twice
23/9
daily
Econazole nitrate twice
daily
Erythema and
scales on soles of feet and maceration between toes
Negative Negative
Negative -
Negative
Griseofulvin
Negative Negative
Griseofulvin
-
Negative
Econazole nitrate twice daily
soles of feet
mo
-
-
daily 20/4
+
daily, griseofulvin
Onychomycosis Hyperkeratosis of soles
16/7
+
Father
rubrum
2y
y/F
ment
Father
Maceration between toes
y/F
15/7
Clotrimazole twice
Nail Involve-
-
No data
12/11
14/12
Naftifine
daily, griseofulvin
toes
10/3
Naftifine
hydrochloride twice daily 6 wk
7/5
Maceration between toes
hydrochloride twice daily
y/M
6/3
Treatment
Family History
-
+ -
rubrum
No data
Econazole nitrate twice daily
Downloaded From: http://archpedi.jamanetwork.com/ by a University of Pennsylvania User on 06/20/2015
Negative
Fig 3.—Diffuse erythematous plaque with fine scale on plantar sur¬ face of foot in a "moccasin distribution, and crusted hemorrhagic papules on toes. "
Fig 1. —frythematous scaly plaques on dorsum of feet and between the toes.
Fig 2.—Scaly erythematous plaques
tar surface
pruritus may also help to distinguish contact dermatitis from tinea pedis. In a study by Weston and as¬ sociates,6 42% of children with dermatitis involving the dorsum of the feet had positive patch test results clinically consistent with an allergic contact dermatitis. Psoriasis may involve the feet, but the thick, scaly plaques usually spare the web spaces, and the heel is of¬ ten severely affected. Nail dystrophy from psoriasis may be impossible to differentiate from tinea pedis without a culture. Erythrasma, a low-grade, chronic, superficial infection of the skin caused by Corynebacterium minutissimum, may also involve the toe webs. However, symmetric patches in the groin and axillae are also often present. Clinically, mild toe web scaling fluoresces bright coral red when ex¬ amined with a Wood's light. Mixed infection may be present; therefore, these patients should also be evalu¬ ated for concurrent tinea pedis. Pitted keratolysis is another superficial infection of the skin caused by a corynebacterium that produces marked hyperkeratosis with multiple 1- to 3-mm punched-out pits on the plantar surface of the foot. These asymptomatic lesions may spread to involve the entire plantar surface, although the heel and sides of the foot are often most se¬ verely affected. Filamentous and coccoid organisms are found in skin scrapings. Tinea pedis is the most common form of dermatophyte infection in the world. The incidence is highest among people who wear occlusive footwear and is much less common in societies where shoes are not worn. The prevalence in industrialized countries approaches 10%.7 Men have a 20% risk of developing athlete's foot.7 The chance of acquiring tinea pedis is also increased in indi¬ viduals who use communal baths or pools and among members of closed communities such as athletic teams or the military. The incidence of tinea pedis in children has not been established. However, the observed increase as one ages is probably a result of greater exposure to infected individuals. The organisms responsible for tinea pedis include Trichophyton rubrum (60%), Trichophyton mentagrophytes (25%), Epidermophyton floccosum (10%), and mixed infec¬ tion (5%).7 Tinea pedis infection can be readily confirmed with a KOH preparation. Branching hyphae can be demonset of
with fissures
of foot and toes.
on
anterior plan¬
tis at other sites also supports the diagnosis of eczema. In "id" or autoeczematization reaction, triggered by tinea pedis, the findings on the hands and feet may mimic dyshidrosis. However, the id reaction is associated with an inflammatory tinea and invariably responds to treatment of the primary infection. Juvenile plantar dermatosis (sweaty-sock syndrome) is readily distinguished from tinea pedis by the typical an
findings of dry, cracked, red, scaly patches on the toe pads and anterior plantar surface of the feet. The toe webs and insteps are invariably spared. Many affected children have a history of atopy and frequently wear sneakers. This condition probably results from repeated wetting of the skin while shoes are worn and drying of the skin when shoes are removed. Sweaty-sock syndrome responds to lubricants and occlusion with socks at night. Allergic contact dermatitis is characterized by involve¬ ment of the dorsal surface of the feet with well-
demarcated, red patches that may contain tiny vesicles. New shoes
or
exposure to other
allergens and acute on-
Downloaded From: http://archpedi.jamanetwork.com/ by a University of Pennsylvania User on 06/20/2015
strated in scale obtained by scraping the inflammatory border of advancing patches or the involved interdigital web spaces. However, artifacts, including thick scale, blood, and air bubbles introduced by accidental boiling of the specimen may obscure these findings. Practitioners who do not routinely perform KOH preparations can demonstrate dermatophyte infection by placing scale di¬ rectly onto dermatophyte test medium. This inexpensive, readily available bottle culture incorporates a phenol red indicator into standard fungal medium. Once inoculated, the culture can be maintained in the office at room tem¬ perature. Dermatophytes usually grow within 2 to 3 weeks. Alkaline metabolites turn the medium red and help to distinguish dermatophytes from contaminants. Positive cultures may also be sent to a reference laboratory for specific identification. Clinically, the most common form of tinea pedis is an intertriginous dermatitis characterized by peeling, mac¬ eration, and fissuring of the lateral toe web spaces. The dermatitis often spreads to involve the undersurface of the toes and occasionally the dorsal surface of the feet. Fissures may develop leading to secondary bacterial infection, particularly with gram-negative organisms. Athlete's foot may also start as dry, scaly patches or hyperkeratotic plaques with mild erythema on the plan¬ tar and lateral surfaces of the foot, yielding a "moccasin" pattern. This papulosquamous variant, which is chronic and extremely resistant to drug therapy, is usually caused by rubrum. Occasionally, tinea pedis presents with an inflamma¬ tory vesiculobullous eruption, which is usually triggered by mentagrophytes. Vesicles and pustules may involve all areas of the foot, with a predisposition for the midanterior plantar surface or instep. This variant occurs most of¬ ten in the summer and may be accompanied by a papulovesicular id reaction on the palms and sides of the fingers. Bacterial superinfection, including lymphangitis, lymphadenitis, and cellulitis may also complicate this clinical presentation. In accordance with the data for adults, most of our pa-
tients demonstrated the intertriginous variant, and ru¬ brum was the most common organism cultured. When questioned about a history of exposure to athlete's foot, most of our patients or their parents could identify a pos¬ sible source. This source was usually one of the parents.
be
In our series, most KOH preparations were reported to
negative. This may reflect the inexperience of tempo¬ rarily rotating residents in pediatrie dermatology clinics.
However, it may also suggest
a
performed. Consequently, the number of children with pedis at our center during the study period was probablythan considerably higher than the 26 reported. 75% of the patients responded well to top¬ More ical antifungal agents applied twice daily. However, sev¬ eral were initially refractory to topical therapy and re¬ quired a course of oral griseofulvin. Our data suggest that tinea pedis is not a rare occur¬ rence in the pediatrie age group. Moreover, tinea pedis tinea
should be considered in any child with foot dermatitis to
prevent a delay in diagnosis and treatment. Careful his¬ tory taking is important to identify sources of infection and
predisposing conditions. Coinfected playmates or family members should also be examined and treated. References 1. Tunnessen WW. Pediatric dermatology. In: Oski FA, ed. Principles and Practice of Pediatrics. Philadelphia, Pa: JB Lippincott; 1990:842-843. 2. Hansen RC. The superficial mycoses (dermatophytosis). In: Kelly VC, ed. Practice of Pediatrics. Philadelphia, Pa: Harper & Row Publisher
Inc; 1987;4:11-12.
3. Hurwitz S. Superficial fungal infections. In: Clinical Pediatric Dermatology. Philadelphia, Pa: WB Saunders Co; 1981:277-292.
4. Jacobs AH, O'Connell MB. Tinea in tiny tots. AJDC. 1986;140:1034\x=req-\ 1038. 5. Caravati CM, Hudgins EM, Kelly LW. Tinea pedis in children. Cutis. 1983;17:313-314. 6. Weston JA, Hawkins K, Weston WL. Foot dermatitis in children.
Pediatrics. 1983;72:324-327. 7. Roberts SOB, Mackenzie DWR. Mycology. In: Rook A, ed. Textbook of Dermatology. Boston, Mass: Blackwell Scientific Publications Inc; 1986:917-921.
In Other AMA
Journals
ARCHIVES OF GENERAL PSYCHIATRY A 2-Year
Prospective Follow-up Study of Children and Adolescents With Disruptive Behavior Disorders: Prediction by Cerebrospinal Fluid 5-Hydroxyindoleacetic Acid, Homovanillic Acid, and Autonomie Measures? Markus J. P. Kruesi, MD; Euthymia D. Hibbs, PhD; Theodore P. Zahn, PhD; Cynthia S. Keysor; Susan D. Hamburger, MS; John J. Bartko, PhD;
Judith L. Rapoport, MD (Arch Gen Psychiatry. 1992;49:429-435) Violence (and
a
selection bias, because
patients with typical clinical disease are often treated em¬ pirically. Moreover, patients with an unequivocally pos¬ itive KOH preparation are also unlikely to have a culture
Message for the 90s?)
Daniel X. Freedman, MD (Arch Gen Psychiatry. 1992;49:485-486)
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McBride, MD, Bernard A. Cohen,
\s=b\ Objective.\p=m-\Todemonstrate that tinea
pedis should be considered in the differential diagnosis of children with foot dermatitis. Design. \p=m-\Patient series. Setting.\p=m-\Outpatientdermatology practice at the Children's Hospital of Pittsburgh (Pa). Participants.\p=m-\Children with culture-proven tinea pedis from 1987 until 1990. Measurements/Main Results. \p=m-\Fungal cultures were used to identify 13 girls and 13 boys ranging in age from 17 months to 18 years with tinea pedis. A parent was the probable source of infection in at least 25% of cases. Conclusions.\p=m-\Tineapedis is not a rare occurrence in children and should be considered in any patient with a foot rash. (AJDC. 1992;146:844-847)
accepted that tinea pedis "athlete's foot" in children.1"3 Moreover, only few anecdotal It isisgenerally and small series of children with tinea or
rare
a
pedis are re¬ ported in the literature.4-5 During the past several years, cases
have treated numerous children with this infection, and we routinely consider this diagnosis in the evaluation of prepubertal children with foot dermatitis. The goal of this study was to document the problem of tinea pedis in the pediatrie age group. We describe our experience with 26 patients to support our clinical im¬ pression that this disorder occurs regularly in children. we
MATERIALS AND METHODS We reviewed the medical records of all patients with tinea pe¬ dis and a positive fungal culture seen in the Pediatrie Dermatol¬ ogy Clinic at the Children's Hospital of Pittsburgh (Pa) from 1987 until 1990. Cases were identified from a diagnostic registry maintained in the hospital clinic area. Patients with a positive potassium hydroxide (KOH) preparation but no record of a fun¬ gal culture were not included in the study. Fungal cultures were obtained by brushing scale and nail shavings directly onto a modified Sabouraud's dextrose agar plate. Cultures were then transported to the microbiology labo¬ ratory at the hospital and maintained at 30°C for 4 weeks. Fungi
Accepted for publication January 27, 1992. From the Department of Dermatology, University of Pittsburgh (Pa) School of Medicine (Dr McBride), and the Departments of Pediatrics and Dermatology, The Johns Hopkins University School of Medicine, Baltimore, Md (Dr Cohen). Reprint requests to Division of Pediatric Dermatology, Johns Hopkins Medical Institutions, 600 N Wolfe St, CMSC 2-116, Baltimore, MD 21205-2104
(Dr Cohen).
MD
identified by specific colony morphologic characteristics microscopic examination. Medical records were reviewed for biographical and historical data, including age at diagnosis, sex, duration of symptoms, physical findings at examination, KOH preparation results, cul¬ ture results, treatment regimen, and family history of tinea pedis. were
and
RESULTS of Twenty-six culture-proven tinea pedis were identified from 1987 until 1990 (Table). This included 13 boys and 13 girls ranging in age from 17 months to 18 years (median age, 7 years). Two children were younger than age 2 years, and 20 (77%) were white. All patients were otherwise healthy. None was taking immunosup¬ pressive agents at the time of consultation. The most common presenting complaint was a scaly, pruritic, erythematous eruption on the plantar and dorsal surfaces of the feet, with maceration in the lateral toe web spaces (Figs 1 through 3). Vesicles were noted in 16% of the patients (n 4). Duration of symptoms ranged from 2 weeks to 12 years (mean, 6 months). Documentation of KOH preparation was recorded in only 50% of the cases. Of these 13 cases, only one was cases
=
positive.
Thirteen of 26 patients, or their parents, were ques¬ tioned about a family history of tinea pedis. Sixty-nine percent (nine of 13) of these patients had a family history of tinea pedis, and the most commonly affected contact was a
parent.
COMMENT Foot dermatitis is a frequent problem in children. Tinea pedis must be differentiated from a number of other dis¬ orders that also produce inflammatory lesions on the feet. Tinea pedis is most commonly confused with eczema or atopic dermatitis. Eczema is characterized by erythema, scaling, and occasionally vesiculation on the palmar and plantar surfaces as well as the top of the hands and feet, particularly over bony prominences and flexures. Chronic disease is associated with lichenification, pigmentary changes, painful Assuring, and a high risk of secondary bacterial infection. Dyshidrosis, a clinical variant of atopic dermatitis, is characterized by intensely pruritic deepseated vesicles on the palms, soles, and sides of the dig¬ its. In eczema, the eruption is symmetric and KOH prep¬ arations and cultures for fungus are negative. A positive personal and family history of atopy and atopic dermati-
Downloaded From: http://archpedi.jamanetwork.com/ by a University of Pennsylvania User on 06/20/2015
Biographical and Case Noy
Duration of
Age/Sex
Symptoms
1/16
y/M
2/18 mo/M
Physical Findings at
Potassium
Examination
1y
Dystrophie great toenails
3
Blisters
mo
on
Historical Data
feet and between
Culture Result
Hydroxide Preparation
Trichophyton
No data
rubrum
Econazole nitrate twice daily
No data
T rubrum
Naftifine
Father
hydrochloride twice daily
toes
3/3
4/4
5/6
y/M
2 wk
y/F
9
mo
y/M
8 6
y/F 8/7 y/F 9/5 y/F
rubrum
No data
Blisters
on
rubrum
feet
No data
Maceration between toes and onychomycosis
rubrum
mo
Maceration between toes and onychomycosis
rubrum
mo
Blisters and
erythema
No data
y/F
11/15
y/F
-
Negative
+
Clotrimazole
No data
+
rubrum
Griseofulvin
Father
No data
Miconazole nitrate
No data
No data
Fine scale on soles of feet and maceration between
rubrum
Clotrimazole twice
No data
-
3
mo
No data
Onychomycosis
daily, griseofulvin rubrum
Scales and erythema on plantar surface of right foot
13/12
y/M
12 y
y/M
6
Dry, scaly feet
mo
3y
No data
Clotrimazole twice
No data
Trichophyton
None
No data
mentagro-
-
phytes
rubrum
mentagro-
No data
None
No data
+
No data
Clotrimazole twice
No data
-
Clotrimazole twice
No data
daily
phytes
rubrum
daily
Maceration between toes
rubrum
-
Clotrimazole twice
Father
daily y/F
17/13 18/10 19/11
-
3
mo
Fine scale and
rubrum
None
No data
y/M
2
mo
Maceration between toes and onychomycosis
rubrum
Clotrimazole twice
Father/ brother
y/M
5y
Maceration between toes
rubrum
Clotrimazole twice
Father
y/M
6y
erythema on plantar surface of feet
daily daily
Blisters between toes
rubrum
21/9
y/M y/M
22/17 mo/F
No data 3 mo
4 mo
Erythema and
scales soles of feet
on
rubrum
Clotrimazole twice No data
Econazole nitrate twice
Erythema and
scales on soles of feet and maceration between toes
Maceration between toes
rubrum
No data
rubrum
No data
y/M
24/18
25/10 26/8
y/F y/F
y/F
Erythema and scales
3 y
No data
3y 15
on
rubrum
soles of feet with fissures
Onychomycosis Erythema and scales on
rubrum
No data
rubrum
daily
Econazole nitrate twice
23/9
daily
Econazole nitrate twice
daily
Erythema and
scales on soles of feet and maceration between toes
Negative Negative
Negative -
Negative
Griseofulvin
Negative Negative
Griseofulvin
-
Negative
Econazole nitrate twice daily
soles of feet
mo
-
-
daily 20/4
+
daily, griseofulvin
Onychomycosis Hyperkeratosis of soles
16/7
+
Father
rubrum
2y
y/F
ment
Father
Maceration between toes
y/F
15/7
Clotrimazole twice
Nail Involve-
-
No data
12/11
14/12
Naftifine
daily, griseofulvin
toes
10/3
Naftifine
hydrochloride twice daily 6 wk
7/5
Maceration between toes
hydrochloride twice daily
y/M
6/3
Treatment
Family History
-
+ -
rubrum
No data
Econazole nitrate twice daily
Downloaded From: http://archpedi.jamanetwork.com/ by a University of Pennsylvania User on 06/20/2015
Negative
Fig 3.—Diffuse erythematous plaque with fine scale on plantar sur¬ face of foot in a "moccasin distribution, and crusted hemorrhagic papules on toes. "
Fig 1. —frythematous scaly plaques on dorsum of feet and between the toes.
Fig 2.—Scaly erythematous plaques
tar surface
pruritus may also help to distinguish contact dermatitis from tinea pedis. In a study by Weston and as¬ sociates,6 42% of children with dermatitis involving the dorsum of the feet had positive patch test results clinically consistent with an allergic contact dermatitis. Psoriasis may involve the feet, but the thick, scaly plaques usually spare the web spaces, and the heel is of¬ ten severely affected. Nail dystrophy from psoriasis may be impossible to differentiate from tinea pedis without a culture. Erythrasma, a low-grade, chronic, superficial infection of the skin caused by Corynebacterium minutissimum, may also involve the toe webs. However, symmetric patches in the groin and axillae are also often present. Clinically, mild toe web scaling fluoresces bright coral red when ex¬ amined with a Wood's light. Mixed infection may be present; therefore, these patients should also be evalu¬ ated for concurrent tinea pedis. Pitted keratolysis is another superficial infection of the skin caused by a corynebacterium that produces marked hyperkeratosis with multiple 1- to 3-mm punched-out pits on the plantar surface of the foot. These asymptomatic lesions may spread to involve the entire plantar surface, although the heel and sides of the foot are often most se¬ verely affected. Filamentous and coccoid organisms are found in skin scrapings. Tinea pedis is the most common form of dermatophyte infection in the world. The incidence is highest among people who wear occlusive footwear and is much less common in societies where shoes are not worn. The prevalence in industrialized countries approaches 10%.7 Men have a 20% risk of developing athlete's foot.7 The chance of acquiring tinea pedis is also increased in indi¬ viduals who use communal baths or pools and among members of closed communities such as athletic teams or the military. The incidence of tinea pedis in children has not been established. However, the observed increase as one ages is probably a result of greater exposure to infected individuals. The organisms responsible for tinea pedis include Trichophyton rubrum (60%), Trichophyton mentagrophytes (25%), Epidermophyton floccosum (10%), and mixed infec¬ tion (5%).7 Tinea pedis infection can be readily confirmed with a KOH preparation. Branching hyphae can be demonset of
with fissures
of foot and toes.
on
anterior plan¬
tis at other sites also supports the diagnosis of eczema. In "id" or autoeczematization reaction, triggered by tinea pedis, the findings on the hands and feet may mimic dyshidrosis. However, the id reaction is associated with an inflammatory tinea and invariably responds to treatment of the primary infection. Juvenile plantar dermatosis (sweaty-sock syndrome) is readily distinguished from tinea pedis by the typical an
findings of dry, cracked, red, scaly patches on the toe pads and anterior plantar surface of the feet. The toe webs and insteps are invariably spared. Many affected children have a history of atopy and frequently wear sneakers. This condition probably results from repeated wetting of the skin while shoes are worn and drying of the skin when shoes are removed. Sweaty-sock syndrome responds to lubricants and occlusion with socks at night. Allergic contact dermatitis is characterized by involve¬ ment of the dorsal surface of the feet with well-
demarcated, red patches that may contain tiny vesicles. New shoes
or
exposure to other
allergens and acute on-
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strated in scale obtained by scraping the inflammatory border of advancing patches or the involved interdigital web spaces. However, artifacts, including thick scale, blood, and air bubbles introduced by accidental boiling of the specimen may obscure these findings. Practitioners who do not routinely perform KOH preparations can demonstrate dermatophyte infection by placing scale di¬ rectly onto dermatophyte test medium. This inexpensive, readily available bottle culture incorporates a phenol red indicator into standard fungal medium. Once inoculated, the culture can be maintained in the office at room tem¬ perature. Dermatophytes usually grow within 2 to 3 weeks. Alkaline metabolites turn the medium red and help to distinguish dermatophytes from contaminants. Positive cultures may also be sent to a reference laboratory for specific identification. Clinically, the most common form of tinea pedis is an intertriginous dermatitis characterized by peeling, mac¬ eration, and fissuring of the lateral toe web spaces. The dermatitis often spreads to involve the undersurface of the toes and occasionally the dorsal surface of the feet. Fissures may develop leading to secondary bacterial infection, particularly with gram-negative organisms. Athlete's foot may also start as dry, scaly patches or hyperkeratotic plaques with mild erythema on the plan¬ tar and lateral surfaces of the foot, yielding a "moccasin" pattern. This papulosquamous variant, which is chronic and extremely resistant to drug therapy, is usually caused by rubrum. Occasionally, tinea pedis presents with an inflamma¬ tory vesiculobullous eruption, which is usually triggered by mentagrophytes. Vesicles and pustules may involve all areas of the foot, with a predisposition for the midanterior plantar surface or instep. This variant occurs most of¬ ten in the summer and may be accompanied by a papulovesicular id reaction on the palms and sides of the fingers. Bacterial superinfection, including lymphangitis, lymphadenitis, and cellulitis may also complicate this clinical presentation. In accordance with the data for adults, most of our pa-
tients demonstrated the intertriginous variant, and ru¬ brum was the most common organism cultured. When questioned about a history of exposure to athlete's foot, most of our patients or their parents could identify a pos¬ sible source. This source was usually one of the parents.
be
In our series, most KOH preparations were reported to
negative. This may reflect the inexperience of tempo¬ rarily rotating residents in pediatrie dermatology clinics.
However, it may also suggest
a
performed. Consequently, the number of children with pedis at our center during the study period was probablythan considerably higher than the 26 reported. 75% of the patients responded well to top¬ More ical antifungal agents applied twice daily. However, sev¬ eral were initially refractory to topical therapy and re¬ quired a course of oral griseofulvin. Our data suggest that tinea pedis is not a rare occur¬ rence in the pediatrie age group. Moreover, tinea pedis tinea
should be considered in any child with foot dermatitis to
prevent a delay in diagnosis and treatment. Careful his¬ tory taking is important to identify sources of infection and
predisposing conditions. Coinfected playmates or family members should also be examined and treated. References 1. Tunnessen WW. Pediatric dermatology. In: Oski FA, ed. Principles and Practice of Pediatrics. Philadelphia, Pa: JB Lippincott; 1990:842-843. 2. Hansen RC. The superficial mycoses (dermatophytosis). In: Kelly VC, ed. Practice of Pediatrics. Philadelphia, Pa: Harper & Row Publisher
Inc; 1987;4:11-12.
3. Hurwitz S. Superficial fungal infections. In: Clinical Pediatric Dermatology. Philadelphia, Pa: WB Saunders Co; 1981:277-292.
4. Jacobs AH, O'Connell MB. Tinea in tiny tots. AJDC. 1986;140:1034\x=req-\ 1038. 5. Caravati CM, Hudgins EM, Kelly LW. Tinea pedis in children. Cutis. 1983;17:313-314. 6. Weston JA, Hawkins K, Weston WL. Foot dermatitis in children.
Pediatrics. 1983;72:324-327. 7. Roberts SOB, Mackenzie DWR. Mycology. In: Rook A, ed. Textbook of Dermatology. Boston, Mass: Blackwell Scientific Publications Inc; 1986:917-921.
In Other AMA
Journals
ARCHIVES OF GENERAL PSYCHIATRY A 2-Year
Prospective Follow-up Study of Children and Adolescents With Disruptive Behavior Disorders: Prediction by Cerebrospinal Fluid 5-Hydroxyindoleacetic Acid, Homovanillic Acid, and Autonomie Measures? Markus J. P. Kruesi, MD; Euthymia D. Hibbs, PhD; Theodore P. Zahn, PhD; Cynthia S. Keysor; Susan D. Hamburger, MS; John J. Bartko, PhD;
Judith L. Rapoport, MD (Arch Gen Psychiatry. 1992;49:429-435) Violence (and
a
selection bias, because
patients with typical clinical disease are often treated em¬ pirically. Moreover, patients with an unequivocally pos¬ itive KOH preparation are also unlikely to have a culture
Message for the 90s?)
Daniel X. Freedman, MD (Arch Gen Psychiatry. 1992;49:485-486)
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