Skin Rash
A rash is inflammation and discoloration that distorts the skin’s appearance. Common skin rashes include COVID-19 rash, eczema, poison ivy, hives, and athlete’s foot.
Rashes may be fungal, bacterial, parasitic, or viral. Over-the-counter products can help treat many skin rashes. Rashes lasting more than a few days should be evaluated by a doctor.
Types of Rashes
Rashes include the following:
COVID-19 Rashes
Skin rashes are associated with coronavirus COVID-19 infections. COVID-19 rashes can take different forms. One study identified five patterns of COVID-19 rash, including a "maculopapular rash." These rashes feature small, flat discolorations and elevated lesions. Other rashes associated with COVID-19 include lesions on the heels, chickenpox-like lesions, and rashes resembling those of dengue fever.
Some dermatologists have reported cases of "COVID toe." These reddish, elevated lesions flatten after about a week. Some patients experience itching or pain, while others do not. More research is needed to determine the cause of these rashes.
Atopic Dermatitis
Atopic dermatitis, or eczema, is a common childhood disorder that produces itchy, weeping rashes on the inner elbows, back of the knees, cheeks, neck, wrists, and ankles.
Seborrheic Dermatitis
Seborrheic dermatitis is the most common rash in adults. It produces a red, itchy eruption that affects the scalp, forehead, brows, cheeks, and ears. In infants, it may involve the scalp and diaper area.
Contact Dermatitis
Contact dermatitis is a rash caused by contact with an allergenic or irritating substance. It tends to be weepy and affects areas that come in direct contact with the substance, like poison ivy or costume jewelry containing nickel.
Diaper Rash
This common irritant contact dermatitis occurs in infants and some adults who wear diapers when feces and urine are in contact with the skin for too long.
Stasis Dermatitis
This weepy dermatitis occurs on the lower legs of individuals with poor circulation in veins.
Psoriasis
This bumpy scaling eruption occurs on the scalp, elbows, and knees. It produces silvery flakes of skin.
Hives
These red, itchy bumps appear suddenly and resolve in about 8 hours. They can recur frequently and may be caused by a drug.
Nummular Eczema
This weepy dermatitis occurs as coin-shaped plaques in the winter and is associated with very dry skin.
Drug Eruptions
Certain drugs can produce a skin rash as a side effect. Drugs may produce various types of rashes.
Heat Rash (Miliaria)
This skin eruption is caused by sweat duct occlusion during hot, humid weather. It looks like a red cluster of acne or small blisters and often occurs on the neck and upper chest, in the groin, under the breasts, and in elbow creases.
Rashes not caused by infectious organisms can be treated with over-the-counter hydrocortisone cream and oral antihistamines to control itching.
Causes of Skin Rashes
Rashes from Fungal Infections
Fungal infections can cause skin rashes, especially in folds of skin. Antifungal creams like clotrimazole and terbinafine are available without a prescription.
If a fungal infection doesn’t respond to treatment, it may be eczema and treated differently.
Rashes from Bacterial Infections
Common bacterial infections of the skin include folliculitis and impetigo. Bacterial rashes are often pustular or plaque-like and painful. Strep throat can cause scarlet fever.
Rash from Parasites
Scabies is a common rash caused by a mite contracted through prolonged contact with an infected individual. Bedbugs cause eruptions where they pierce the skin.
Viral Exanthems
Rashes that occur with viral infections are called exanthems. They can affect the entire body or be localized. Most resolve on their own.