The word “rash” is a general term for an outbreak of bumps, spots, marks or patches on the body. Affected skin will feel and look different. A rash can affect many different parts of the body at the same time or be localized in nature. While rashes are generally not dangerous, they can be hard to diagnose accurately. A visit to a doctor or health professional is strongly advised.
Atopic dermatitis (Eczema)
A very common form of chronic skin rash that is thought to be associated with allergies and tends to be hereditary. Commonly referred to as eczema, the rash can flare-up and subside in an irregular pattern. There may be long dormant periods between out breaks. It’s often very difficult to assign a seasonal variation or link a flare up to a particular allergen such as foods, soaps or detergents.
The skin becomes very itchy and inflamed. It can look read and swollen at times. Other times the skin will weep, scale and crust. The condition is not contagious. Treatment involves minimizing the irritation and using steroid creams (generally cortisone) at prescription or over-the-counter concentrations. Non steroidal creams are also available but opinions vary as to their effectiveness.
Contact dermatitis
An itching skin rash that occurs as a result of contact with a specific material (e.g nickel in jewelry, rubber, perfume, poison ivy, poison oak) or a specific action (e.g. too frequent hand washing, too much lip licking in the case of angular cheilitis) that causes an allergic reaction and/or secondary infection. Key to treatment is avoiding the allergen that has caused it. Treatments include topical application of steroids and over the counter strength hydrocortisone. Anti itch creams and antihistamines may also help.
Skin rashes caused by fungal infections
Often referred to by the generic term, ringworm, a fungal rash tends to affect areas of the body that are warm, moist and protected. The rash is generally a crimson red color and may have pustules or ridges around the edges. Note that some “fungus” infections are caused by the yeast Candida albicans, which botanically is related to a fungus. Treatment is relatively effective using over the counter antifungal creams such as Lotrimin cream. Prescription creams are also available. See more on fungus on skin. If the fungus progresses to the nail, in a condition known as Onychomycosis, treatment is more complicated. Read more on nail fungus treatment.
Hives
A fast evolving dry itching rash that can change in a matter of hours. Hives that last longer than 6 weeks are known as “chronic hives” while “acute hives” describes cases that last less than 6 weeks. The risk factors are numerous and it is not always possible to identify a single causal agent.
Pityriasis rosea (Christmas tree rash)
A common dry skin rash with a ring like appearance known as a “herald patch.” The rash tends to be very itchy with fine scales lasting several weeks. Given its rink like appearance it is sometime confused with ringworm. The intense itchiness of the rash can be relieved with oral antihistamines and topical steroids. The rash is more common in people under the age of 35 and normally resolves on its own. The cause is unknown.
Psoriasis
A chronic skin condition that is caused by an overactive immune response. It is characterized by rough, thick scaly patches of skin with a red base and distinct border. It often occurs on the knees, scalp and elbows and tends to flare up periodically. Psoriasis is a complicated skin disorder and it is vital to see a dermatologist before attempting to self-treat. More information.
Heat rash
There are two forms of common heat rash. The first, known as millaria, occurs when sweat pores are obstructed (for example by tight-fitting clothes). The second, prickly heat, produces a pricking or stinging sensation. Nether is serious.
Shingles
Cased by the chicken pox virus, the shingles rash takes the form of small blisters that itch, burn or tingle. The blisters can burst leeching behind crusty ulcers. Your doctor may recumbent antiviral drugs or vaccination depending on your age and severity of the condition. More information.