The Differential Diagnosis of Systemic Sclerosis

Alan Tyndall; Susanna Fistarol

Disclosures

Curr Opin Rheumatol. 2013;25(6):692-699. 

In This Article

Scleromyxoedema

Also known as papular mucinosis and lichen myxoedematosus, scleromyxoedema is a very rare condition characterized by increased mucinous deposition in the skin, monoclonal gammopathy and waxy skin eruption. First described in 1953,[12] it has recently undergone a re-classification to include both systemic and localized forms.[13] It has an equal sex distribution, mostly affects middle-aged persons and has not been described in children. Symmetric skin thickening, induration and progressive tightening with firm, waxy, closely spaced, lichenoid, often itchy papules typically affects the forehead with deep longitudinal furrowing of the glabella, posterior auricular and neck (Fig. 3a). But face (with reduced mouth opening and rigid facial expressions; Fig. 3b), forearms and hands, including sclerodactyly (Fig. 4), and thighs may resemble SSc. However, the typical involvement of skin in the middle of the back in scleromyxoedema (Fig. 5) is not seen in SSc. Extracutaneous manifestations may include the cardiovascular, pulmonary, renal, gastrointestinal and central nervous system, but vasculopathy such as Raynaud's phenomenon and telangiectasiae is not a feature.

Figure 3.

Typical facial involvement of scleromyxoedema with longitudinal furrowing of the glabella (a) and reduced mouth opening (b).

Figure 4.

The hand in scleromyxoedema showing sclerodactyly but no Raynaud's phenomenon, digital ulcer.

Figure 5.

Skin involvement of the mid back in scleromyxoedema (not seen in systemic sclerosis).

Almost all cases have an IgGλ gammopathy in blood and skin lesions, and in-vitro experiments have suggested that the serum contains a fibroblast-stimulating factor.[14] However, purified patients' immunoglobulin did not do this.

The skin biopsy shows diffuse mucin deposition in the middle and deeper dermis displacing collagen fibres, fragmented elastic fibres, proliferation of fibroblasts and, unlike NSF, a slight superficial, perivascular, lymphoplasmacytic inflammatory cell infiltrate (Fig. 6). Similarities and differences between scleromyxoedema and SSc are shown in Table 1. The treatment outcome in scleromyxoedema is rather bleak: most immunosuppressive agents have been tried with limited success. High-dose intravenous immunoglobulins produced some improvement. In view of the gammopathy, and following the experience of primary amyloidosis, autologous hematopoietic stem cell transplantation has been attempted, sometimes with success.[15]

Figure 6.

Both scleromyxoedema (a) and nephrogenic system fibrosis (b) show mucin and collagen deposition, but in nephrogenic systemic fibrosis, there are few inflammatory cells.

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