Punctate porokeratosis-pruritic and hyperkeratotic papules on the palms and feet

Porokeratosis is an uncommon cutaneous condition with multiple clinical variants that is defined by round patches with a raised, fine scaling border. Punctate porokeratosis is a rare variant of porokeratosis that is characterized by elevated, seed-like lesions of the palms and soles. While variants of porokeratosis may be associated with an increased risk of squamous cell carcinoma within the lesion, punctate porokeratosis does not increase the risk of squamous cell carcinoma. However, punctate porokeratosis may mimic other dermatoses affecting the palms and soles including spiny keratoderma, arsenical keratosis, and nevus comedonicus. Distinguishing punctate porokeratosis and spiny keratoderma is important, as spiny keratoderma may be associated with underlying solid organ malignancy or chronic medical conditions, including chronic kidney disease. Here, we present a case of punctate porokeratosis mimicking spiny keratoderma in order to distinguish the two conditions and aid in their differentiation from other dermatologic conditions involving the palms and soles.