dermatology; skin of color; skin cancer; Fitzpatrick skin types; skin pigmentation; skin pigment; porokeratosis; dermatology; skin; porokeratosis; porokeratosis of Mibelli; linear porokeratosis; dermoscopy; cornoid lamella; neoplasm; squamous cell carcinoma


Dermatology | Neoplasms | Pathological Conditions, Signs and Symptoms | Skin and Connective Tissue Diseases


Porokeratosis was first described in 1893. It is a relatively rare disorder with over 9 subtypes. Lesions are clinically characterized as well-demarcated, erythematous papules (raised, <1 cm) or plaques (raised, >1 cm), with an atrophic center, and raised scaly border. Porokeratosis is an important diagnosis to identify because it may undergo malignant transformation and mimics many commonly encountered diagnoses. These commonly mimicked diagnoses include squamous cell carcinoma, tinea corporis, nummular dermatitis, and psoriasis vulgaris, to name a few. The clinical images in this review focus on identifying porokeratosis along the full spectrum of skin tones.