BRIEF REPORTS Pediatric Dermatology Vol. 32 No. 1 147–157, 2014
Recurrent Pustular Eruption Masquerading as Pustular Psoriasis in Netherton Syndrome
counseled about the prognosis. The patient had two further episodes of pustular eruptions. Further follow-up until 1 year of age showed recurrent episodes of erythema and scaling, without any pustular lesions. DISCUSSION
Abstract: We report a unique presentation of Netherton syndrome with recurrent pustular eruptions leading to an erroneous diagnosis of infantile pustular psoriasis. Light microscopy of eyebrow hair showed trichorrhexis invaginata, consistent with Netherton syndrome.
We report a 3-month-old Indian infant with congenital erythroderma, failure to thrive, and recurrent pustular eruptions, which led to an erroneous diagnosis of infantile pustular psoriasis, but microscopy of eyebrow hair showed trichorrhexis invaginata, suggestive of Netherton syndrome. CASE REPORT A 3-month-old infant, the product of a nonconsanguineous marriage, was referred for diffuse erythema and scaling, recurrent pustular eruptions, fever, and multiple episodes of diarrhea soon after birth. A provisional diagnosis of infantile seborrheic dermatitis and psoriatic erythroderma was made based on diffuse erythema and greasy scaling, predominantly over flexures. Oral prednisolone (1 mg/kg/day) was initiated, with partial response. Eruption of fresh crops of pustules with erythematous bases over the right lower limb and trunk along with fever followed tapering of prednisolone. Pustules rapidly coalesced to form lakes of pus (Fig. 1). Pus culture was sterile. Histopathology of a pustule was suggestive of pustular psoriasis, so acitretin (0.5 mg/kg/day) was given, followed by cyclosporine (3 mg/kg/day), with partial response and subsidence of pustules and erythema, although episodes of pustular eruption continued. Hematologic investigations revealed microcytic hypochromic anemia, neutrophilic leukocytosis, and high erythrocyte sedimentation rate. Absolute eosinophil count was 1,100 cells/lL. C-reactive protein (>6 mg/L) and serum immunoglobulin (IgE) (457 IU/mL) levels were high. The patient also developed hypernatremia (154 mEq/L). Microscopy of his eyebrow hair showed bamboo hairs (trichorrhexis invaginata) (Fig. 2). A revised diagnosis of Netherton syndrome was made and his parents were
© 2014 Wiley Periodicals, Inc.
Netherton syndrome is a rare autosomal recessive genodermatosis caused by mutations of both copies of the SPINK5 gene (localized to band 5q31-32), which encodes the serine protease lymphoepithelial Kazaltype-related (LEKTI) (1). Each SPINK5 mutation leads to a different length of LEKTI protein, resulting in genotype and phenotype correlations in cutaneous severity, susceptibility to atopic dermatitis, growth retardation, skin infection, stratum corneum protease activity, and high kallikrein levels in the stratum corneum. The syndrome is characterized by congenital ichthyosiform erythroderma, ichthyosis linearis circumflexa, trichorrhexis invaginata, and atopic diathesis with failure to thrive (1). Although congenital erythroderma was the initial presentation in our patient, recurrent crops of pustules and histopathology were characteristic of pustular psoriasis. Poor response to oral steroids, cyclosporine, and acitretin, along with high IgE levels, eosinophilia, and failure to thrive prompted us to perform hair microscopy despite normal scalp hair. Finally, eyebrow hair showed trichorrhexis invaginata, consistent with Netherton syndrome. Congenital psoriasis and Netherton syndrome can present as neonatal erythroderma with overlapping clinical features in the form of anemia, failure to thrive, scaling, and recurrent skin infections. Moreover, both conditions show partial response to emollients, topical and systemic steroids, and oral immunosupressive medications, blurring clinical differentiation between the two. In developing countries such as India, genetic testing for specific mutations such as SPINK5 is prohibitively expensive. Because examination of the scalp hair might not initially show the characteristic abnormality of Netherton syndrome, repeated microscopy of eyebrow hair is recommended to make an early diagnosis. This case highlights an unusual cutaneous presentation of Netherton syndrome in the form of recurrent pustular eruptions, leading to an erroneous diagnosis of pustular psoriasis. It also underscores the importance of eyebrow hair microscopy, which may provide an early clue to the correct diagnosis of Netherton syndrome in the absence of a genetic test.
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Figure 1. Coalescing pustules over erythematous skin involving the right lower limb and trunk forming lakes of pus (arrow).
Ulcerated Spitz Nevus Masquerading as a Juvenile Xanthogranuloma Abstract: We report a case of ulcerated atypical Spitz nevi that demonstrated a yellow to light orange background under dermoscopy, which can be seen in juvenile xanthogranuloma (JXG) and is referred to as the “setting sun” appearance. This yellow to orange appearance was due to serous crusting and not histiocytic infiltration, which is seen in JXG. This case highlights overlapping dermatoscopic features between the two skin lesions and polymorphous vascular structures, which are unique to atypical Spitz nevi.
Figure 2. Microscopy of eyebrow hair showing bamboo hair (trichorrhexis invaginata) (109).
REFERENCE 1. Chavanas S, Bodemer C, Rochat A et al. Mutations in SPINK5, encoding a serine protease inhibitor, cause Netherton syndrome. Nat Genet 2000;25:141–142. Vibhu Mendiratta, M.D.* Pravesh Yadav, M.D.* Ram Chander, M.D.* Shilpi Aggarwal, M.D.† *Department of Dermatology and Sexually Transmitted Diseases and †Department of Pathology, Lady Hardinge Medical College and Suchita Kriplani Hospital, Shaheed Bhagat Singh Marg, Delhi, India Address correspondence to Pravesh Yadav, RZ-97, Phase III, Prem Nagar, Najafgarh, New Delhi 110043, India, or e-mail: rao. [email protected].
A healthy 17-month-old girl presented to our pediatric dermatology clinic for an enlarging lesion on the forehead. The parents reported a small pimple-like lesion 2 months prior that grew rapidly and did not resolve with mupirocin. They denied preceding trauma. The grandfather had a history of melanoma. Clinical examination revealed a well-circumscribed 0.5-cm 9 0.5-cm dome-shaped red to yellow papule with central superficial crusting on the forehead (Fig. 1). Dermoscopy was remarkable for a homogeneously pigmented yellow to light orange lesion with scattered dotted, comma-like, and serpentine vascular structures (Fig. 2). Because of the yellow to light orange dermoscopic pattern, a diagnosis of juvenile xanthogranuloma (JXG) was favored over that of a Spitz nevus.
Recurrent Pustular Eruption Masquerading as Pustular Psoriasis in Netherton Syndrome
counseled about the prognosis. The patient had two further episodes of pustular eruptions. Further follow-up until 1 year of age showed recurrent episodes of erythema and scaling, without any pustular lesions. DISCUSSION
Abstract: We report a unique presentation of Netherton syndrome with recurrent pustular eruptions leading to an erroneous diagnosis of infantile pustular psoriasis. Light microscopy of eyebrow hair showed trichorrhexis invaginata, consistent with Netherton syndrome.
We report a 3-month-old Indian infant with congenital erythroderma, failure to thrive, and recurrent pustular eruptions, which led to an erroneous diagnosis of infantile pustular psoriasis, but microscopy of eyebrow hair showed trichorrhexis invaginata, suggestive of Netherton syndrome. CASE REPORT A 3-month-old infant, the product of a nonconsanguineous marriage, was referred for diffuse erythema and scaling, recurrent pustular eruptions, fever, and multiple episodes of diarrhea soon after birth. A provisional diagnosis of infantile seborrheic dermatitis and psoriatic erythroderma was made based on diffuse erythema and greasy scaling, predominantly over flexures. Oral prednisolone (1 mg/kg/day) was initiated, with partial response. Eruption of fresh crops of pustules with erythematous bases over the right lower limb and trunk along with fever followed tapering of prednisolone. Pustules rapidly coalesced to form lakes of pus (Fig. 1). Pus culture was sterile. Histopathology of a pustule was suggestive of pustular psoriasis, so acitretin (0.5 mg/kg/day) was given, followed by cyclosporine (3 mg/kg/day), with partial response and subsidence of pustules and erythema, although episodes of pustular eruption continued. Hematologic investigations revealed microcytic hypochromic anemia, neutrophilic leukocytosis, and high erythrocyte sedimentation rate. Absolute eosinophil count was 1,100 cells/lL. C-reactive protein (>6 mg/L) and serum immunoglobulin (IgE) (457 IU/mL) levels were high. The patient also developed hypernatremia (154 mEq/L). Microscopy of his eyebrow hair showed bamboo hairs (trichorrhexis invaginata) (Fig. 2). A revised diagnosis of Netherton syndrome was made and his parents were
© 2014 Wiley Periodicals, Inc.
Netherton syndrome is a rare autosomal recessive genodermatosis caused by mutations of both copies of the SPINK5 gene (localized to band 5q31-32), which encodes the serine protease lymphoepithelial Kazaltype-related (LEKTI) (1). Each SPINK5 mutation leads to a different length of LEKTI protein, resulting in genotype and phenotype correlations in cutaneous severity, susceptibility to atopic dermatitis, growth retardation, skin infection, stratum corneum protease activity, and high kallikrein levels in the stratum corneum. The syndrome is characterized by congenital ichthyosiform erythroderma, ichthyosis linearis circumflexa, trichorrhexis invaginata, and atopic diathesis with failure to thrive (1). Although congenital erythroderma was the initial presentation in our patient, recurrent crops of pustules and histopathology were characteristic of pustular psoriasis. Poor response to oral steroids, cyclosporine, and acitretin, along with high IgE levels, eosinophilia, and failure to thrive prompted us to perform hair microscopy despite normal scalp hair. Finally, eyebrow hair showed trichorrhexis invaginata, consistent with Netherton syndrome. Congenital psoriasis and Netherton syndrome can present as neonatal erythroderma with overlapping clinical features in the form of anemia, failure to thrive, scaling, and recurrent skin infections. Moreover, both conditions show partial response to emollients, topical and systemic steroids, and oral immunosupressive medications, blurring clinical differentiation between the two. In developing countries such as India, genetic testing for specific mutations such as SPINK5 is prohibitively expensive. Because examination of the scalp hair might not initially show the characteristic abnormality of Netherton syndrome, repeated microscopy of eyebrow hair is recommended to make an early diagnosis. This case highlights an unusual cutaneous presentation of Netherton syndrome in the form of recurrent pustular eruptions, leading to an erroneous diagnosis of pustular psoriasis. It also underscores the importance of eyebrow hair microscopy, which may provide an early clue to the correct diagnosis of Netherton syndrome in the absence of a genetic test.
147
148 Pediatric Dermatology Vol. 32 No. 1 January/February 2015
Figure 1. Coalescing pustules over erythematous skin involving the right lower limb and trunk forming lakes of pus (arrow).
Ulcerated Spitz Nevus Masquerading as a Juvenile Xanthogranuloma Abstract: We report a case of ulcerated atypical Spitz nevi that demonstrated a yellow to light orange background under dermoscopy, which can be seen in juvenile xanthogranuloma (JXG) and is referred to as the “setting sun” appearance. This yellow to orange appearance was due to serous crusting and not histiocytic infiltration, which is seen in JXG. This case highlights overlapping dermatoscopic features between the two skin lesions and polymorphous vascular structures, which are unique to atypical Spitz nevi.
Figure 2. Microscopy of eyebrow hair showing bamboo hair (trichorrhexis invaginata) (109).
REFERENCE 1. Chavanas S, Bodemer C, Rochat A et al. Mutations in SPINK5, encoding a serine protease inhibitor, cause Netherton syndrome. Nat Genet 2000;25:141–142. Vibhu Mendiratta, M.D.* Pravesh Yadav, M.D.* Ram Chander, M.D.* Shilpi Aggarwal, M.D.† *Department of Dermatology and Sexually Transmitted Diseases and †Department of Pathology, Lady Hardinge Medical College and Suchita Kriplani Hospital, Shaheed Bhagat Singh Marg, Delhi, India Address correspondence to Pravesh Yadav, RZ-97, Phase III, Prem Nagar, Najafgarh, New Delhi 110043, India, or e-mail: rao. [email protected].
A healthy 17-month-old girl presented to our pediatric dermatology clinic for an enlarging lesion on the forehead. The parents reported a small pimple-like lesion 2 months prior that grew rapidly and did not resolve with mupirocin. They denied preceding trauma. The grandfather had a history of melanoma. Clinical examination revealed a well-circumscribed 0.5-cm 9 0.5-cm dome-shaped red to yellow papule with central superficial crusting on the forehead (Fig. 1). Dermoscopy was remarkable for a homogeneously pigmented yellow to light orange lesion with scattered dotted, comma-like, and serpentine vascular structures (Fig. 2). Because of the yellow to light orange dermoscopic pattern, a diagnosis of juvenile xanthogranuloma (JXG) was favored over that of a Spitz nevus.
