Amyloidosis is a rare condition that occurs when amyloid, an abnormal protein, builds up in the body. Amyloidosis can spread through the body and negatively affect many major organs, such as the heart, kidneys, lungs, and nervous system. While amyloidosis doesn’t specifically target the skin, people with the condition may experience skin-related symptoms. After all, the skin is the body’s largest organ.
Amyloidosis that affects primarily the skin is known as primary localized cutaneous amyloidosis (PLCA). This article will explain how amyloidosis can affect the skin, why it occurs, and what people with the condition can do to treat it.
Not every person with amyloidosis will have symptoms that affect the skin. People with secondary systemic amyloidosis, for example, rarely develop skin involvement. Generally speaking, people who experience skin symptoms have PLCA.
PLCA occurs when amyloid proteins build up into clusters called dermal papillae between the top two layers of the skin, the epidermis and dermis. This accumulation can cause patches of skin to look or feel unusual, though skin symptoms vary depending on the type of PLCA a person has.
There are three main types of PLCA:
Symptoms for each type typically begin in mid-adulthood. These symptoms may disappear and return at different times, or they can persist for months or years at a time.
The most common form of PLCA, lichen amyloidosis, causes scaly, thick, reddish-brown patches or raised spots. These spots often develop on the shins, legs, feet, and forearms. Patches are usually very itchy and may develop many tiny bumps.
A person with macular amyloidosis might develop flat, dark brown or gray, mildly itchy skin patches on the upper back, torso, or limbs. These patches may look rippled or lacy, though more often they have a uniform color and texture.
Nodular amyloidosis (also known as nodular localized cutaneous amyloidosis) causes red, pink, or brown bumps (nodules) to form on the face, limbs, torso, or genitals. These nodules are often firm and raised, but they usually aren’t itchy.
As with all forms of the condition, amyloidosis that affects the skin occurs when abnormally folded proteins build up in tissue and organs and limit their functionality. It is not known what causes conditions like nodular localized cutaneous amyloidosis to develop. The same is true of lichen amyloidosis, though some researchers believe lichen amyloidosis may be brought on by scratching the skin.
Although most people with PLCA seem to develop the condition randomly, researchers have noted that PLCA can run in families. Some people with primary cutaneous amyloidosis develop the condition as the result of an inherited mutation (change) in the OSMR or IL31RA genes.
Primary cutaneous amyloidosis has also been found to be associated with other skin conditions, including atopic dermatitis (eczema), psoriasis, and sarcoidosis. More research is needed to determine the factors that cause certain people to develop amyloidosis of the skin.
Currently, there is no cure for amyloidosis. There is also no one recommended treatment for PLCA. For certain types of PLCA, such as lichen amyloidosis, some therapies may be helpful in managing symptoms like itching or reducing the appearance of lesions. These treatments include:
Ultimately, more high-quality studies (such as randomized controlled clinical trials) are needed to identify successful treatments for PLCA.
Amyloidosis is a rare disease, but you’re not alone. MyAmyloidosisTeam is the social media network for people with amyloidosis and their loved ones. Members come together to ask questions, give advice, and share their experiences with others who understand life with amyloidosis.
Has amyloidosis affected your skin? Leave a note in the comments below, or start a conversation by posting on MyAmyloidosisTeam.