Focal Dermal Hypoplasia: A Male Case

A 17-year-old male presented with multiple linear distributed erythema and papules which first appeared since birth. The erythema was fragile, easily traumatized, and often healed with hypopigmented atrophic scars. The right first and second fingers and nails were hypoplastic. Generalized linear or whorled hyperpigmented patches gradually developed and multiple papillomatous papules emerged during childhood, which were mainly distributed in the perioral region. A skin biopsy found epidermal parakeratosis, diminished dermal thickness, increased vasculatures in dermal papillae, and upward migration of subcutaneous fat layer known as “fat herniation”. A diagnosis of focal dermal hypoplasia was thus established.