LAUSR

A 4-year-old boy presented with a 4-month history of small coalescing pustules set within asymptomatic vegetating and ulcerative plaques on the eyelids, upper lip and gingiva, palate and penis (Fig. 1a–c). There were no systemic problems. The patient’s medical and family history was unremarkable. Laboratory studies revealed peripheral blood eosinophilia (0.86 9 10/L with 10.90% eosinophils; normal ranges 0.0– 0.5 9 10/L and 0.4%–8%), but all other tests, including chemistry profile, C-reactive protein, erythrocyte sedimentation rate, antinuclear antibody and double-stranded DNA antibody gave normal results. Tests for perinclear and cytoplasmic antineutrophil cytoplasmic antibodies, anti-Saccharomyces cerevisiae antibody, pancreatic autoantibody and goblet cell autoantibody were negative. Stool analysis was normal. Negative results were found for fecal occult blood test; ELISA for BP180-NC16a, desmoglein (Dsg)1 and Dsg3; indirect immunofluorescence; bacterial and fungal swabs; and serological tests for HIV and syphilis. A biopsy was taken from a lesion on the oral mucosa.