Pityriasis rosea (Christmas tree rash) diagnosis and treatment. Sometimes pityriasis can be mistaken for other skin diseases. For instance, it has been accidentally diagnosed as ringworm or a type of eczema called nummular dermatitis. In many cases, it is a dermatologist who diagnoses the Christmas tree rash.
With an allergy, it may be a day or two before the rash shows up. Symptoms of a contact allergy are usually right around where you touched the thing you're allergic to. Irritant contact dermatitis (skin damage) tends to burn and be more painful than itchy. Treating a Rash at Home. If you know what caused the rash, don't touch it again.
Most drug rashes result from an allergic reaction to the drug. Usually the reaction is to a drug taken by mouth or injected. The drug does not have to be applied to the skin to cause a drug rash. When the immune system comes into contact with a drug, it can become sensitive to that drug (a process called sensitization).
Miliaria crystallina is the most common and mildest form of heat rash. If you have miliaria crystallina, you’ll notice small clear or white bumps filled with fluid on the surface of your skin. These bumps are bubbles of sweat. The bumps often burst. Contrary to popular belief, this type of heat rash doesn’t itch and shouldn’t be painful.
Lichen planus is a skin rash triggered by the immune system. It’s not known why the immune response occurs. There may be several contributing factors, and each case is different. Potential causes include: viral infections; allergens; stress; genetics; Sometimes lichen planus occurs along with autoimmune disorders.
Tinea is a type of fungal infection that resembles some symptoms of psoriasis. Psoriasis can cause the thick fingernails symptomatic of fungal nail infections, and both can cause red skin rashes that itch. When tinea grows on your skin, it can cause a scaly, red skin rash that clears in the middle, called ringworm (pictured). Fungal infections of the skin and nails can be hard to treat. Antifungal medications work, but you may need to take them for a long time.