Lichen Myxedematosus

The terms lichen myxedematosus, papular mucinosis, and scleromyxedema are used to describe different forms of the same disorder, a chronic connective tissue disorder in which mucin deposits form in the skin. Lichen myxedematosus or papular mucinosis refers to the less severe form that is limited to the skin. Scleromyxedema refers to the rare, more severe form in which other body systems are affected in addition to the skin.

The cause of lichen myxedematosus and scleromyxedema is not known. The diseases affect both males and females and individuals of all ethnic backgrounds. Symptoms usually begin in adulthood.

Symptoms
Lichen myxedematosus or papular mucinosis – Bumps (papules), either skin-colored or reddened, appear on the skin, and may form groups. The papules may have a pattern of parallel ridges. Papules are found on the backs of the hands, on the face, or the arms and legs. The ridges and folds of the face may be distorted, with ridges and furrows developing on the brow and cheeks. This is known as leonine (“lion-like”) facies (leontiasis).
Scleromyxedema – Areas of red, raised skin appear, and the skin becomes tight like in scleroderma. There is difficulty moving the face, fingers, and arms and legs. Scleromyxedema also causes problems with the lungs and breathing, and with the heart and circulation. It may cause muscle weakness and joint pain, and neurological symptoms like those in brain disease, such as seizures, may be present.

Diagnosis
Diagnosis of lichen myxedematosus and scleromyxedema is based on the symptoms the individual is experiencing, especially what the skin looks like. A special blood test for a paraprotein (7S-IgG) can be done, and is usually positive. Other laboratory tests, including thyroid function tests, are normal. Skin and tissue samples can be examined under a microscope for deposits of mucin, which are characteristic of the disease.

Treatment
Many types of treatment for lichen myxedematosus and scleromyxedema have been tried in small numbers of people in research studies, but none has been consistently effective in reducing symptoms. Symptoms may improve with the use of high-dose dexamethasone and/or thalidomide, but over time the symptoms may return or even worsen. Chemotherapy drugs such as melphalan have also been tried, but without consistent success in treatment.

Individuals with lichen myxedematosus and scleromyxedema have long-term, often disfiguring, and possibly disabling disorders. The risks and benefits of drug treatment should be carefully considered.

Research
Researchers at the University of Texas M.D. Anderson Cancer Center studied eight individuals with scleromyxedema who had the disease for 3-1/2 years and had other symptoms in addition to the skin symptoms. All the individuals underwent high dose chemotherapy with melphalan followed by autologous stem cell transplantation. Seven of the eight individuals had a marked improvement in their symptoms after the transplant. In five individuals, the skin symptoms resolved completely. The researchers concluded that high-dose melphalan appears to be a safe and effective treatment, but also recommended further studies be done. The research was published in the January 15, 2006, issue of Blood.

Information for this article was taken from:
- Donato, M.L., et al. Scleromyxedema: Role of high-dose melphalan with autologous stem cell transplantation. Blood, 107; 415, pp. 463-466
- Liotta, E. A. (2005). Lichen myxedematosus. eMedicine, accessed at http://www.emedicine.com/derm/topic231.htm
- Scleromyxedema Survivors