Bullous prurigo pigmentosa following a ketogenic diet

On physical examination, multiple scaly erythematous papules and brownish macules coalescing into plaques and patches arranged in a reticulate pattern on the chest, back, sacrum, and mons pubis. Direct microscopy examination of scrapings from the scaly papules on the chest showed negative for fungi. Histopathologically, extensive inflammation with intercellular and intracellular edema, basal liquefaction, and papillary dermal edema may result in vesiculobullous lesions.