Rongioletti and Rebora reported criteria for scleromyxedema and localized lichen myxedematosus (LM).
Criteria for scleromyxedema:
(1) generalized papular and sclerodermoid eruption
(2) microscopic changes - one or both of the following:
(2a) triad of dermal mucin deposition, thickened collagen, and fibroblast proliferation
(2b) interstitial granuloma annulare-like pattern
(3) evidence of monoclonal gammopathy
(4) exclusion of thyroid disease
where:
• The requirements for monoclonal gammopathy and exclusion of thyroid disease are controversial.
• Scleromyxedema should have systemic symptoms.
Criteria for localized lichen myxedematosus is similar to scleromyxedema except
(1) the first item is localized.
(2) monoclonal gammopathy is absent.
(3) systemic symptoms are absent.
Subtypes of localized lichen myxedematosus:
(1) discrete papules at a single site
(2) acral persistent papular mucinosis on the extensor surfaces of the hands and wrists
(3) self-healing papular mucinosis
(4) papular mucinosis of infancy
(5) nodular
An intermediate or atypical category is used to describe a patient with features greater than localized LM and less than scleromyxedema (more than local, local plus monoclonal gammopathy, generalized lesions without monoclonal gammopathy, generalized lesions without systemic symptoms).
