Primary localized cutaneous amyloidosis (PLCA) is characterized by heterogeneous extracellular deposition of amyloid proteins in the skin without systemic involvement. Types of PLCA include the following:
- Macular amyloidosis
- Papular amyloidosis
- Nodular amyloidosis
Macular amyloidosis is an itchy disease that varies in severity and consists of small gray-brown macules that are symmetrically distributed on the upper part of the back of the shoulder and, in some patients, the arms. Most patients are treated because of hyperpigmentation and skin appearance.
Macular amyloidosis is thought to result from a combination of genetic and environmental causes with long-term friction. However, the exact molecular mechanisms are not known.
Macular amyloidosis is a chronic disease. Disfigurement and severe itching significantly impair the quality of life. In a study of 101 Chinese patients with PLCA, Fang et al reported that mean scores in social functioning and quality of life were significantly reduced due to pruritus. Management of pruritus is an important component of treatment because of its significant effect on quality of life. In addition, this study showed that lesions on visible parts of the body, such as the face and hands, reduce quality of life more than lesions that can be hidden.
Treatment:
Treatment includes anti-itching drugs, topical drugs, DMSO, etc. The duration of treatment is long and all patients may not respond to the treatment to the same extent.
The important part of the treatment is to avoid scratching and causing wear on the skin, because this will increase the amount of darkening of the skin.
