Acral persistent papular mucinosis.

Acral persistent papular mucinosis is a rare subtype of localized lichen myxedematosus. For half a century, this disease has endured a controversial and constantly evolving classification. We describe a patient who presented with discrete, flesh-colored papules on the hands, wrists, and forearms in a distribution consistent with acral persistent papular mucinosis. Histology was also constant with this disease, showing a well-circumscribed deposition of mucin in the upper and mid dermis that spared a small grenz zone. The changing nomenclature and diagnostic requirements of acral persistent papular mucinosis that have allowed it to remain a topic of debate are examined through a comprehensive review of the literature. All reported cases are reviewed.