Dermatology Online Journal

Papular mucinosis
Jeremy E. Rothfleisch
Dermatology Online Journal 7(2): 13

New York University Department of Dermatology

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History

his 66-year-old man was referred to the Charles C. Harris Skin and Cancer Pavilion with a two-year history of multiple, firm, skin-colored papules on the ears, forehead, cheeks, knees, and elbows. Since a biopsy had been performed by the referring physician, the patient was treated with cyclosporine and prednisone.

Physical Examination

Figure 1	Figure 2

He had multiple, 0.1-to-0.4-cm, firm, skin-colored papules were noted on the ears, forehead, cheeks, elbows, and knees. The voice was hoarse.

Laboratory Data

The white-cell count was 18.3 x 109/L, serum glucose 141 mg/dl, and serum cholesterol 242 mg/dl. Liver and renal function studies were normal. A serum protein electrophoresis was ordered but not obtained.

Histopathology

Within the superficial dermis there were deposits of mucin associated with a proliferation of plump fibroblasts.

Comment

There is confusion with regard to the terminology of this entity in the literature. There are localized cases and disseminated cases called papular mucinosis or lichen myxedematosus and generalized, confluent papular forms with sclerosis called scleromyxedema. Although papular mucinosis is frequently used as a synonym for all three forms, some authors restrict it to only mild cases. Acral persistent papular mucinosis is now considered to be a separate entity.

This condition is rare and affects adults of both sexes equally and appears between ages 30 and 80. It is chronic and may be progressive. The primary lesions are waxy, 2-to-4-mm, dome-shaped or flat-topped papules. Frequently, they may coalesce into plaques or appear in a linear array. Less frequently, urticarial, nodular, or sometimes annular lesions may be appreciated. The dorsal aspect of the hands, face, elbows, and extensor portions of the extremities are most frequently affected. Mucosal lesions are absent. The coalescence of papules on the face, particularly of the glabella, results in longitudinal folding and gives the appearance of a leonine facies.

In scleromyxedema, large parts of the body may be involved; the skin shows erythematous, scleroderma-like induration that is accompanied by reduced mobility of the lips, hands, arms, and legs. Systemic manifestations have been described, such as proximal myopathy, inflammatory polyarthritis, central nervous system symptoms, esophageal aperistalsis, and hoarseness. Visceral involvement of scleromyxedema may be fatal.

Laboratory studies show an abnormal paraprotein in 90% of cases, usually of the IgG-8 type. This underlying suggestion of a plasma-cell dyscrasia prompts examination of the bone marrow, which may be normal or show increased numbers of plasma cells or even myeloma. Histologic examination shows a horizontal band of mucinous material between collagen bundles in the upper dermis. This material is a glycosaminoglycan that stains with alcian blue at pH 2.5 and is susceptible to hyaluronidase digestion. There is an increase in the number of fibroblasts and dermal fibrosis.

Treatment of this condition remains unsatisfactory. Topical therapy is of no benefit. Clearance of lesions has been reported with melphalan and cyclophosphamide alone or in combination with prednisone. Both isotretinoin and etretinate have been associated with improvement. Interferon-alpha, cyclosporine, PUVA photochemotherapy, electron-beam therapy, IVIg, and dermabrasion have also been attempted. The overall prognosis for extensive disease is poor.

References

Howden SM, et al. Lichen myxedematosus: a dermal infiltrate disorder responsive to cyclophosphamide therapy. Arch Dermatol 111:1325, 1975

Clark BJ, et al. Papular mucinosis. Br J Dermatol 135:467, 1996

Bata-Csorgo Z, et al. Scleromyxedema. J Am Acad Dermatol 41:343, 1999

Tschen JA, Chang JR. Scleromyxedema: treatment with interferon alpha. J Am Acad Dermatol 40:303, 1999

Liiter RK, et al. Scleromyxedema: response to high-dose intravenous immunoglobulin (hdIVIg). J Am Acad Dermatol 43:403, 2000

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