What is macular amyloidosis?

Macular amyloidosis is a skin or skin condition characterized by flat, discolored patches of skin called macules. It falls into the category of disorders called amyloidosis, which involves the deposition of amyloid proteins in organs or tissues of the body. This type of buildup usually causes damage to the affected areas by preventing normal function.

The macules that characterize macular amyloidosis are pruritic, meaning they produce a severe itching sensation. Brown or gray are the usual manifestations of pigmentation, the usual site of occurrence being the upper back. In some cases, the rashes appear on the arms.

Macular amyloidosis is one of three conditions in the category of primary cutaneous amyloidosis, as well as the most common. The other two are lichen amyloidosis, which is characterized by solid pruritic lichenoid elevations of the skin; and nodular amyloidosis, named for its small, rounded lumps. Each condition is associated with the receptor protein known as the Oncostatin-M-specific receptor beta subunit, or Oncostatin-M receptor. Some medical researchers believe that mutations of this substance can lead to the appearance of such diseases.

Although the exact cause of macular amyloidosis is still unknown, the medical community has proposed two main possibilities. The first hypothesis is called the fibrillary body theory, which suggests that two groups of cells: fibroblasts, which function as connective tissue cells; and macrophages, white blood cells that eat substances that pose a risk of infection: they convert prematurely dead cells in the epidermis, or outer layer of skin, into amyloid. The other explanation, the secretory theory, suggests that it is the basal cells, found in the innermost epidermal layer, that form the amyloid when they break down.

Macular amyloidosis is a condition that only affects adults. Studies have shown that the disease is more common in women than in men. Also, it tends to occur more often among South Americans, Asians, and Orientals.

There are different types of treatment methods for macular amyloidosis. Antihistamines or histamine antagonists, such as chlorpheniramine and diphenhydramine, are used to inhibit the organic compound histamine, thus reducing allergies; and agents such as dimethyl sulfoxide are applied to reduce inflammation. Other treatment methods include the application of ultraviolet B (UV-B) light and surgical excision of the macules. However, a fully effective or successful cure for macular amyloidosis has yet to be devised or discovered, and the disease remains long-lasting and extremely difficult to eradicate.

Go up