Skin rash on chest and back
If a rash affects the chest and back, it may be the bran fungus lichen, which is caused by the skin fungus Malassezia furfur. This yeast fungus is part of the healthy skin flora in all people. Brownish spots are formed, which remain light in comparison to the surrounding skin when exposed to sunlight.
This fungus is not contagious and the disease is harmless. Another cause of a rash on the chest and back can be seborrhoeic eczema, in which, in addition to the reddish rash, dandruff and itching can occur and which also frequently affects the hairy scalp, adjacent areas and the face. This can lead to cosmetic problems, but also to bacterial colonization of the affected skin.
Infections with chickenpox, measles or tropical pathogens can also cause skin rashes on the chest and back. Shingles, which can occur in people with weakened immune systems, can also affect the chest and back.The pathogen is the Varicella zoster virus, which triggers chickenpox and can then remain in the nerves and be reactivated in case of immunodeficiency. The rash usually follows a dermatome, which corresponds to the skin area of the inflamed, affected nerve.
Skin rash on chest and arms
If the chest and arms are affected by a skin rash, it can be neurodermatitis, also known as atopic eczema. This rash is red, dry, scaly and itchy, but is not contagious. Often children are affected and the disease “grows together” with aging.
In many cases people with neurodermatitis also have allergies such as hay fever or suffer from asthma. Another common clinical picture is psoriasis. Here, red, blotchy plaques form, which are covered with yellowish scales.
Other places where psoriasis can occur are the scalp or knees, but also the back. In some cases, those affected also have accompanying joint problems. An allergic reaction to a drug can also lead to a skin rash, the so-called drug exanthema, which starts at the trunk of the body and then spreads and is characterized by many small red spots and papules, similar to measles. Typically, mucous membranes are also affected and often antibiotics such as sulfonamides or painkillers are the triggers.