Epidemic Norwegian Scabies in a Geriatric Unit A. H. HOPPER, J. SALISBURY, A. N. JEGADEVA, B. SCOTT, G. C. J. BENNETT
Norwegian scabies is highly contagious and presents with a psoriasiform dermatosis. It afflicts particularly the elderly and patients with immunosuppression. Two weeks after the admission of an index case of Norwegian scabies to a geriatric ward, 13 of 25 patients and 6 of 18 ward nurses developed scabies. Despite comprehensive treatment, the ward epidemic recurred 6 weeks later probably as a result of inadequate treatment of the index case. This diagnosis should be considered when patients from highrisk groups present with an undiagnosed rash.
Introduction Scabies has persisted with high incidence since the mid-1970s, although incidence among elderly people remains low [1]. Norwegian (crusted) scabies is a rare variant in which infestation with the scabies mite, Sarcoptes scabiei produces a psoriasiform dermatosis of the hands and feet and an erythematous scaling eruption that may become generalized. It was first described in the 1840s in Norwegian patients with leprosy [2] but was not reported in England until 1950 [2]. Norwegian scabies is highly contagious and may produce hospital epidemics [3]. We describe an epidemic occurring on a ward for elderly people following the admission of a case of Norwegian scabies.
The Outbreak In August 1988, an 81-year-old woman was admitted to a 25-bed mixed acute and continuing-care ward for elderly patients. Her medical history included diet-controlled diabetes mellitus and a previous stroke. She presented with
drowsiness and decreased mobility. On examination she had an 'eczematous' rash on her arms, trunk and legs with areas of hyperkeratosis on her hands and feet. This was diagnosed by a non-dermatologist as eczema. Two weeks after her admission, patients and nurses began to develop an itchy rash. Scabies was diagnosed by a dermatologist after identification of burrows on patients, although scrapings taken from six patients did not show S. scabiei. Scabies was diagnosed in 13 of 25 patients, in all of whom burrows were identified and in 6 of 18 nurses who presented with a papular rash on the forearms without identifiable burrows. No other ward staff developed scabies. Management of the outbreak: The index case was isolated in a side room and barrier-nursed. Nurses and ward staff wore gloves and gowns until the outbreak was cleared. Patients and staff diagnosed as having scabies and the index case's daughter who remained asymptomatic were treated with a daily application of l ° 0 lindane (gamma benzene hexachloride) lotion for 3 days. On the third day, all other ward staff (n = 20) were treated with a single application of Age and Ageing 1 990;19:125-1 27
Downloaded from http://ageing.oxfordjournals.org/ at Florida Atlantic University on June 8, 2016
Summary
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A. H. HOPPER ET AL.
Discussion The pathogenesis of Norwegian scabies is uncertain but it is reported to occur in patients with altered cutaneous sensation in leprosy [2] or diabetes mellitus, and in association with altered cell-mediated immunity due to immunosuppressant drugs [4], topical corticosteroids [5], acquired immunodeficiency syndrome or malnutrition. In elderly subjects age-associated alteration in lymphocyte function may be important. Lack of itching due to reduced hypersensitivity, or the inability of the host to respond to irritation by scratching may prevent the elimination of the mite. The more widespread use of immunosuppressant drugs and the rising prevalence of acquired immunodeficiency syndrome in the community may increase the incidence of Norwegian scabies. A typical case of scabies is not highly contagious. The mean number of adult female mites on the skin is approximately 11 and more than half the cases carry less than five mites [6]. In contrast, Norwegian scabies is highly contagious. Total skin mite population may be
several million [7] and both bed-linen and the immediate environment may be heavily infested with epithelial and crust material containing the mite in large numbers, up to 6300 mites/g [8]. Moreover, as the rash is atypical, diagnosis of Norwegian scabies is often delayed until an epidemic has occurred. The failure of the initial treatment to halt the epidemic may have resulted from an inadequate ward decontamination, although as the survival of the mite in the environment is very short this is unlikely to be important. More probably the recurrence resulted from persistence of the mites in the nodules of hyperkeratinized skin of the index case. Keratolytic treatment of such areas is an important part of management. Some concern has been expressed over the toxicity of lindane [9]. It has been reported to cause convulsions and coma in children, aplastic anaemia, and may be immunotoxic, although the reports are usually of overdose or exposure to insecticidal preparations. Approximately 9% of topically applied lindane is absorbed [10]. The index case remained drowsy and apathetic throughout her hospital admission and died of bronchopneumonia 4 months afterwards. Her plasma lindane concentration 1 week after completion of the final treatment was 73 nmol/1 although, because it is highly lipophilic, brain lindane concentration may have been greater and it may persist in adipose tissue. Workers who have been exposed to lindane may develop tiredness and influenza-like symptoms when plasma concentrations are above 75 nmol/1 [11]. The index case's non-specific symptoms may represent 'low-grade' intoxication to which elderly subjects may be particularly prone owing to reduced drug clearance. Norwegian scabies should be considered in any elderly or immunosuppressed patient with an unexplained generalized rash and the patient isolated until it can be excluded. In an epidemic, the rash developing on healthy members of staff is typically a papular rash on the forearms which is thought to result from follicular irritation caused by non-burrowing immature forms of 5. scabiei [8], or by hypersensitivity to the mite's faeces. In a nursing home or continuing-care ward, comprehensive treatment of the whole ward is required to eradicate the epidemic.
Downloaded from http://ageing.oxfordjournals.org/ at Florida Atlantic University on June 8, 2016
lindane for 1 day and all ward linen was collected and laundered. Ward visitors and other contacts were advised to consult a doctor if they developed symptoms. After treatment, itching developed in four patients and 6 of 20 non-infested ward staff. Recurrence of outbreak: Six weeks after completion of treatment, the index case and two patients developed active scabies. The scabies cases were treated with lindane for a further 3 days and ward staff and non-infested patients were again treated for 1 day. The index case was transferred to an isolation ward and was treated using 1 % lindane cream twice weekly, lindane shampoo, i strength betamethasone valerate and keratolytic agents (urea 40% with salicylic acid 10%) applied to finger-nails and areas of hyperkeratosis. After a further 6 weeks, her rash including the areas of hyperkeratosis had resolved. She was then transferred back to the general ward although nail treatment and weekly application of 1 % lindane cream was continued for 3 weeks. No further evidence of scabies has been observed since.
Acknowledgements We are grateful to Dr Elizabeth Shaw, Department of Medical Microbiology, and Dr Irene Leigh, Department of Dermatology, for guidance on the management of this outbreak. Dr L. Drummond, Health and Safety Executive, Organic Toxicology Laboratory performed the lindane assays.
References 1. Christophersen J. The epidemiology of scabies in Denmark, 1900 to 1975. Arch Dermato! 1978;114:747-S0. 2. Calnan CD. Crusted scabies. Br J Dermatol 1950;62:71-8. 3. Reilly S, Cullen D, Davies MG. An outbreak of scabies in a hospital and community. Br Med jf 1985,291:1031-2. 4. Youshock E, Glazer SD. Norwegian scabies in a renal transplant patient. JAMA 1981;246:26089. 5. Millard LG. Norwegian scabies developing during treatment with fiuorinated steroid therapy. Ada Dermatol Venereol 1977;57:86-8. 6. Mellanby K. Biology of the parasite. In: Orkin M, Maibach HI, eds. Cutaneous infestations and insect bites. New York: Dekker, 1985;9-18.
127
7. Pirila V, Salo OP, Kiistala R. Scabies Norvegica. Acta Dermatol Venereol 1967,47:267-8. 8. Carslaw RW, Dobson RM, Hood AJK, Taylor RN. Mites in the environment of cases of Norwegian scabies. Br J Dermatol 1975,92:3337. 9. Wilkinson C. Is the treatment of scabies hazardous? J R Coll Gen Pract 1988;38:468-9. 10. Hosier J, Tschanz C, Hignite CE, Azarnoff DL. Topical application of lindane cream (kwell) and antipyrine metabolism, jf Invest Dermatol 1979;74:51-3. 11. Drummond L, Gillanders EM, Wilson HK. Plasma gamma-hexachlorocyclohexane concentrations in forestry workers exposed to lindane. Brjf Ind Med 1988;45:493-7. Authors' addresses A. Hopper, A. N. Jegadeva, B. Scott, G. C. J. Bennett Department of Geriatric Medicine, J. Salisbury Department of Dermatology, The London Hospital (Mile End), Bancroft Road, London El 4DG Received in revised form 27 April 1989
ordjournals.org/ at Florida Atlantic University on June 8, 2016
NORWEGIAN SCABIES IN A GERIATRIC UNIT
Norwegian scabies is highly contagious and presents with a psoriasiform dermatosis. It afflicts particularly the elderly and patients with immunosuppression. Two weeks after the admission of an index case of Norwegian scabies to a geriatric ward, 13 of 25 patients and 6 of 18 ward nurses developed scabies. Despite comprehensive treatment, the ward epidemic recurred 6 weeks later probably as a result of inadequate treatment of the index case. This diagnosis should be considered when patients from highrisk groups present with an undiagnosed rash.
Introduction Scabies has persisted with high incidence since the mid-1970s, although incidence among elderly people remains low [1]. Norwegian (crusted) scabies is a rare variant in which infestation with the scabies mite, Sarcoptes scabiei produces a psoriasiform dermatosis of the hands and feet and an erythematous scaling eruption that may become generalized. It was first described in the 1840s in Norwegian patients with leprosy [2] but was not reported in England until 1950 [2]. Norwegian scabies is highly contagious and may produce hospital epidemics [3]. We describe an epidemic occurring on a ward for elderly people following the admission of a case of Norwegian scabies.
The Outbreak In August 1988, an 81-year-old woman was admitted to a 25-bed mixed acute and continuing-care ward for elderly patients. Her medical history included diet-controlled diabetes mellitus and a previous stroke. She presented with
drowsiness and decreased mobility. On examination she had an 'eczematous' rash on her arms, trunk and legs with areas of hyperkeratosis on her hands and feet. This was diagnosed by a non-dermatologist as eczema. Two weeks after her admission, patients and nurses began to develop an itchy rash. Scabies was diagnosed by a dermatologist after identification of burrows on patients, although scrapings taken from six patients did not show S. scabiei. Scabies was diagnosed in 13 of 25 patients, in all of whom burrows were identified and in 6 of 18 nurses who presented with a papular rash on the forearms without identifiable burrows. No other ward staff developed scabies. Management of the outbreak: The index case was isolated in a side room and barrier-nursed. Nurses and ward staff wore gloves and gowns until the outbreak was cleared. Patients and staff diagnosed as having scabies and the index case's daughter who remained asymptomatic were treated with a daily application of l ° 0 lindane (gamma benzene hexachloride) lotion for 3 days. On the third day, all other ward staff (n = 20) were treated with a single application of Age and Ageing 1 990;19:125-1 27
Downloaded from http://ageing.oxfordjournals.org/ at Florida Atlantic University on June 8, 2016
Summary
126
A. H. HOPPER ET AL.
Discussion The pathogenesis of Norwegian scabies is uncertain but it is reported to occur in patients with altered cutaneous sensation in leprosy [2] or diabetes mellitus, and in association with altered cell-mediated immunity due to immunosuppressant drugs [4], topical corticosteroids [5], acquired immunodeficiency syndrome or malnutrition. In elderly subjects age-associated alteration in lymphocyte function may be important. Lack of itching due to reduced hypersensitivity, or the inability of the host to respond to irritation by scratching may prevent the elimination of the mite. The more widespread use of immunosuppressant drugs and the rising prevalence of acquired immunodeficiency syndrome in the community may increase the incidence of Norwegian scabies. A typical case of scabies is not highly contagious. The mean number of adult female mites on the skin is approximately 11 and more than half the cases carry less than five mites [6]. In contrast, Norwegian scabies is highly contagious. Total skin mite population may be
several million [7] and both bed-linen and the immediate environment may be heavily infested with epithelial and crust material containing the mite in large numbers, up to 6300 mites/g [8]. Moreover, as the rash is atypical, diagnosis of Norwegian scabies is often delayed until an epidemic has occurred. The failure of the initial treatment to halt the epidemic may have resulted from an inadequate ward decontamination, although as the survival of the mite in the environment is very short this is unlikely to be important. More probably the recurrence resulted from persistence of the mites in the nodules of hyperkeratinized skin of the index case. Keratolytic treatment of such areas is an important part of management. Some concern has been expressed over the toxicity of lindane [9]. It has been reported to cause convulsions and coma in children, aplastic anaemia, and may be immunotoxic, although the reports are usually of overdose or exposure to insecticidal preparations. Approximately 9% of topically applied lindane is absorbed [10]. The index case remained drowsy and apathetic throughout her hospital admission and died of bronchopneumonia 4 months afterwards. Her plasma lindane concentration 1 week after completion of the final treatment was 73 nmol/1 although, because it is highly lipophilic, brain lindane concentration may have been greater and it may persist in adipose tissue. Workers who have been exposed to lindane may develop tiredness and influenza-like symptoms when plasma concentrations are above 75 nmol/1 [11]. The index case's non-specific symptoms may represent 'low-grade' intoxication to which elderly subjects may be particularly prone owing to reduced drug clearance. Norwegian scabies should be considered in any elderly or immunosuppressed patient with an unexplained generalized rash and the patient isolated until it can be excluded. In an epidemic, the rash developing on healthy members of staff is typically a papular rash on the forearms which is thought to result from follicular irritation caused by non-burrowing immature forms of 5. scabiei [8], or by hypersensitivity to the mite's faeces. In a nursing home or continuing-care ward, comprehensive treatment of the whole ward is required to eradicate the epidemic.
Downloaded from http://ageing.oxfordjournals.org/ at Florida Atlantic University on June 8, 2016
lindane for 1 day and all ward linen was collected and laundered. Ward visitors and other contacts were advised to consult a doctor if they developed symptoms. After treatment, itching developed in four patients and 6 of 20 non-infested ward staff. Recurrence of outbreak: Six weeks after completion of treatment, the index case and two patients developed active scabies. The scabies cases were treated with lindane for a further 3 days and ward staff and non-infested patients were again treated for 1 day. The index case was transferred to an isolation ward and was treated using 1 % lindane cream twice weekly, lindane shampoo, i strength betamethasone valerate and keratolytic agents (urea 40% with salicylic acid 10%) applied to finger-nails and areas of hyperkeratosis. After a further 6 weeks, her rash including the areas of hyperkeratosis had resolved. She was then transferred back to the general ward although nail treatment and weekly application of 1 % lindane cream was continued for 3 weeks. No further evidence of scabies has been observed since.
Acknowledgements We are grateful to Dr Elizabeth Shaw, Department of Medical Microbiology, and Dr Irene Leigh, Department of Dermatology, for guidance on the management of this outbreak. Dr L. Drummond, Health and Safety Executive, Organic Toxicology Laboratory performed the lindane assays.
References 1. Christophersen J. The epidemiology of scabies in Denmark, 1900 to 1975. Arch Dermato! 1978;114:747-S0. 2. Calnan CD. Crusted scabies. Br J Dermatol 1950;62:71-8. 3. Reilly S, Cullen D, Davies MG. An outbreak of scabies in a hospital and community. Br Med jf 1985,291:1031-2. 4. Youshock E, Glazer SD. Norwegian scabies in a renal transplant patient. JAMA 1981;246:26089. 5. Millard LG. Norwegian scabies developing during treatment with fiuorinated steroid therapy. Ada Dermatol Venereol 1977;57:86-8. 6. Mellanby K. Biology of the parasite. In: Orkin M, Maibach HI, eds. Cutaneous infestations and insect bites. New York: Dekker, 1985;9-18.
127
7. Pirila V, Salo OP, Kiistala R. Scabies Norvegica. Acta Dermatol Venereol 1967,47:267-8. 8. Carslaw RW, Dobson RM, Hood AJK, Taylor RN. Mites in the environment of cases of Norwegian scabies. Br J Dermatol 1975,92:3337. 9. Wilkinson C. Is the treatment of scabies hazardous? J R Coll Gen Pract 1988;38:468-9. 10. Hosier J, Tschanz C, Hignite CE, Azarnoff DL. Topical application of lindane cream (kwell) and antipyrine metabolism, jf Invest Dermatol 1979;74:51-3. 11. Drummond L, Gillanders EM, Wilson HK. Plasma gamma-hexachlorocyclohexane concentrations in forestry workers exposed to lindane. Brjf Ind Med 1988;45:493-7. Authors' addresses A. Hopper, A. N. Jegadeva, B. Scott, G. C. J. Bennett Department of Geriatric Medicine, J. Salisbury Department of Dermatology, The London Hospital (Mile End), Bancroft Road, London El 4DG Received in revised form 27 April 1989
ordjournals.org/ at Florida Atlantic University on June 8, 2016
NORWEGIAN SCABIES IN A GERIATRIC UNIT
