Ultrastructural signs of altered intracellular metabolism in acral persistent papular mucinosis

Acral persistent papular mucinosis

Acral persistent papular mucinosis (APPM) is a subtype of localized lichen myxedematosus (LM) characterized by the chronic development of white to skin-colored papules and limited to the extensor surfaces of the hands and distal part of forearms, in the absence of systemic or laboratory manifestations. There is a strong predominance in women. Histopathology shows focal accumulation of mucin in the upper portion of the dermis sparing the grenz zone. The etiology is unknown. It is a benign condition, although dynamic changes occur with the progressive development of additional lesions. No specific treatment is required, and patients should be reassured about the prognosis.

Acral persistent papular mucinosis: a case report and literature review

Acral persistent papular mucinosis is a rare subtype of localized lichen myxedematosus. It shows symmetric, asymptomatic, chronic, ivory to flesh-colored, 2-5 mm sized papules arranged on the dorsa of the hands and extensor aspects of the distal forearms. Thirty-two cases including two from China, appear to fit the proposed diagnostic criteria. We report a 31-year-old Chinese woman who presented with papules on the extensor aspects of her hands and distal forearms. Histopathology revealed a circumscribed area in the upper and mid reticular dermis with splaying of collagen fibers caused by amorphous deposits. The material was mucin, as it stained positively with alcian blue at pH 2.5. The thyroid profile was normal, and there was no evidence for lupus erythematous. The lesions were treated with electrofulguration and resolved leaving mild scars; there has been no recurrence at follow-up after one year. We also review the literature on this rare form of mucinosis.

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.

Type I and type III collagens in cutaneous mucinosis

Cutaneous mucinoses are a heterogeneous group of diseases characterized by the focal or diffuse dermal deposition of glycosaminoglycans. The histopathologic examination of many cutaneous mucinoses reveals that the collagen fibers are fragmented. We wanted to characterize the type I (COL1) and type III (COL3) collagen distribution in skin biopsy specimens of patients with cutaneous mucinosis. The diagnosis of mucinosis was based on a modification of the classification by Rongioletti and Rebora: four patients had familial papulonodular mucinosis: four had papular mucinosis, one of which was associated with myxedema and one had scleromyxedema; and one had focal mucinosis. We performed anti-type I and type III collagens immunolabeling on frozen sections. Immunofluorescence for COL1 was increased in the superficial dermis of 2/4 familial papulonodular mucinosis, in 5/5 of papular mucinosis, and in scleromyxedema and focal mucinosis cases. The mid-dermis showed intense staining for COL1 at the periphery of collagen bundles and, in three cases of familial papulonodular mucinosis and two cases of papular mucinosis, a lacy appearance. The superficial dermis of familial papulonodular mucinosis specimens and of papular mucinosis + myxedema, scleromyxedema, and focal mucinosis specimens had decreased COL3 staining. The mid-dermis showed a more prominent fibrillar staining at the periphery of the collagen bundles, and two cases of papular mucinosis showed intense labeling for COL3. Both COL1 and COL3 distributions are altered in cutaneous mucinosis. An intense labeling with COL1 is predominantly found in the superficial layer of cutaneous mucinosis. Cases of FTP revealed decreased COL3 reactivity at the superficial layer.

Acral persistent papular mucinosis in two sisters

We describe two young sisters with an asymptomatic papular eruption on the forearms, the clinical, histopathological and ultrastructural features of which were consistent with acral persistent papular mucinosis. Familial occurrence of this uncommon disease is exceptional.