Nofal et al reported criteria for making the diagnosis of lichen myxedematosus. The authors are from Zagazig University, Al-Haud Al-Marsoud Dermatology Hospital and Al-Azhar Unviersity in Cairo.
Patient selection: suspected lichen myxedematosus
Constant features:
(1) firm, waxy, closely-set papules that coalesce into indurated plaques or nodules
(2) diffuse deposition of mucin in the dermis and fibroblastic proliferation, with or without fibrosis
Variable associations:
(1) monoclonal gammopathy
(2) thyroid disease (usually hypothyroidism)
(3) HIV infection
(4) hepatitis C viral infection
(5) peripheral eosinophilia
(6) thymic or hepatocellular carcinoma
(7) interstitial granuloma annulare-like pattern
A definite diagnosis requires both of the constant features.