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.