Spiny keratoderma (SK) was first described by Brown in 1871 and is characterized by numerous 1-2 mm spines of keratin on the palms and soles, usually sparing the dorsal surfaces, or disseminated over the trunk. Histologically, the "spine" represents a column of hyperkeratosis. Several different forms are known, including familial, sporadic, post-inflammatory and paraneoplastic. Although an association of SK with melanoma has been reported, the significance of such co-occurrence remains unclear due to the limited number of cases. To increase the body of knowledge and shed further light on this rare condition, we present a case of SK in a patient with a recent history of melanoma in situ.
Keywords: filiform hyperkeratosis; follicular hyperkeratosis; melanoma in situ; porokeratosis punctata palmaris et plantaris; punctate porokeratosis; spiny keratoderma.