Sarcoidosis is an illness that causes cells of the body to be inflamed. Sarcoidosis is a rather mysterious condition in that the cause remains unknown. The lymph nodes and lungs are the most commonly affected parts of the body. Sarcoidosis affects the lungs in about ninety percent of patients. Sarcoidosis can also affect other parts of the body. Someone with sarcoidosis may have inflammation of numerous parts of the body including the liver, heart, nervous system, or other body organs or systems.

Sarcoidosis can also affect the skin. Twenty to thirty-five percent of sarcoidosis cases involve some effect to the skin. In about one third of the people with sarcoidosis affecting the skin, the sarcoidosis does not affect any other parts of the body. Besides an eczema rash, the sarcoidosis may cause itchiness. Eczema from sarcoidosis can appear in vastly different forms.

Atopic dermatitis sarcoidosis is abnormalities of the skin caused by sarcoidosis. Sarcoidosis can affect the skin in a variety of ways. The skin may develop brown or purplish skin lesions. Another form of atopic dermatitis sarcoidosis can cause the formation of calcium salts within the skin. The formation of calcium salts in the skin is called calcinosis cutis.

Some types of atopic dermatitis sarcoidosis can affect various types of the body though some types target specific areas of the body. One type of eczema from sarcoidosis causes lesions and purplish nodules on the nose, ears, cheeks, toes, and fingers. Atopic dermatitis sarcoidosis can cause one to two centimeter bumps on the skin of the shins which may occur with arthritis of the wrists and ankles.

Sarcoidosis can also cause nummular eczema, also known as discoid eczema. Nummular eczema may have wet or dry rashes. The wet type of nummular eczema often forms blisters and becomes crusted. Nummular eczema often appears as red, pink, or brown bumpy patches that are round or oval.

Existing scars can be affected by sarcoidosis. Scar sarcoidosis is a thickening of old scars due to sarcoidosis. Though many types of eczema from sarcoidosis are superficial, it can also cause deep lesions.

Erythema multiforme is a temporary skin condition that can be caused by a reaction to medication, sarcoidosis, or another illness. Erythema multiforme causes a blistering rash. It often affects the mouth and forearms, but it can affect other areas of the body. This skin condition may last for up to three weeks. Though it is relatively short term, erythema multiforme may recur.