By Gary M. White, MD
Cutaneous mucin deposition may occur in association with a paraprotein usually of the IgG-lamba type. When multiple papules occur, the term lichen myxedematosus is used (also papular mucinosis). When confluent with underlying induration, the term scleromyxedema is used. Diffuse deposition of mucin may occur internally although life expectancy is usually not affected. Gastrointestinal involvement is most common, manifested by e.g. dysphagia. Other systemic manifestations include dyspnea on exertion, hypogonadism, hypothyroidism, diabetes mellitus and proximal muscle weakness.
Hematologic malignancies commonly develop including acute leukemia, non-Hodgkin's lymphoma and multiple myeloma. In one case where a serum paraprotein was not found, skin biopsy showed a plasma cell infiltrate that was monotypic for lamda light chain, and putatively neoplastic [BJD 1996;135;467].
Also note that the association between focal cutaneous mucinosis and internal malignancies such as gastric, pancreatic, lung, and ovarian neoplasms has been reported in the past, but that the exact certainty of this association is unclear [Dermatology Online Journal 23(3)].
Innumerable uniform 2-3 mm skin-colored papules along the arms, neck and face occur in lichen myxedematosus. Onset is typically between ages 30 and 50. A variable amount of erythema or a dusky violaceous color may be seen.
Therapy is usually carried out by an oncologist using various chemotherapeutic drugs typically used to treat myeloma, e.g. melphalan, dexamethasone, thalidomide, etc.
IVIG has shown great benefit for scleromyxedema. In a study of 8 patients treated for a mean of 36 months, a clinical scoring system documented an improvement of 82% [JEADV 2017;31;1157]. Their standard regimen for IVIG is one cycle/month dosed at 2 g/kg per month administered over a course of 4-5 days. It has been combined with thalidomide [Case Rep Dermatol. 2013 Nov 2;5(3):309-15].
Five patients with scleromyxedema [JAAD Dec 2013] were treated for 6 months with the combination of pulse steroid therapy, sirolimus, and octreotide. The exact regimen was pulse steroid (dexamethasone) 120 mg intramuscularly over 2 consecutive days/week, octreotide 200 g subcutaneously every other day, and oral sirolimus 1 mg twice daily. All patients remained in remission off treatment for 3 to 24 months (13 ± 2 months).
Dermatology Online Journal 21(3)
72 year-old man with plaque like cutaneous mucinosis. He was found to have a cancer of pancreatobiliary origin. After several months of chemotherapy, his skin lesions improved. Dermatology Online Journal 21(2)
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