Reticulate acropigmentation of Kitamura (RAPK) is a rare autosomal dominantly inherited pigmentary disorder characterized by slightly depressed hyperpigmented reticulated papules on the dorsal hands and feet. Onset is typically at age 5-12 years, and progression with involvement of the distal extremities is seen over ensuing years. The lesions tend to gradually darken over time. They can also darken with exposure to the sun and may be more prominent in the summer. In addition to these features, patients with RAPK also have palmoplantar pits and breaks in the creases of the palms, soles, and fingers.

RAPK was first described in the Japanese population, and it has since been documented in many ethnic groups around the world. RAPK is seen more commonly in females than in males.

RAPK is caused by a mutation in the ADAM10 gene on chromosome 15q21.