Diagnosis: Reticulate acropigmentation of Kitamura (RAPK).
MICROSCOPIC FINDINGS AND CLINICAL COURSE
Hematoxylin-eosin–stained sections showed basilar hyperpigmentation predominantly located at the tips of elongated rete ridges. Melanocytes did not appear to be increased in number. The dermis was devoid of solar elastosis.
Therapeutic options are limited. Azelaic acid therapy may reduce the hyperpigmentation.1 In our case, neither topical azelaic acid nor 4% hydroquinone therapy was effective over a 6-month period.
DISCUSSION
Reticulate acropigmentation of Kitamura is one of a group of autosomal dominant pigmentary disorders that also includes Dowling-Degos disease (DDD) and reticulate acropigmentation of Dohi (RAPD). It can also appear sporadically, as in our case. Kanehiko Kitamura, MD, of Nagasaki, Japan, first described RAPK in 1943. Additional cases have been reported from other parts of the world.2
Reticulate acropigmentation of Kitamura presents in the first through the third decades of life, typically around puberty, as slowly progressive, reticulated pigmentation of the extremities. The pigmentation usually involves the extensor surfaces of the extremities, . . . [Full Text of this Article]
