An erythematous rash is characterized by redness resulting from skin inflammation surrounding a patch of skin where a rash is located. This type of rash falls into one of three categories: nodosum, photosensitivity and multiforme. Numerous irritants might cause the rash to form on a person’s skin, requiring a medical professional to properly determine the source of the rash, as well as prescribe proper treatment.
Common symptoms of an erythematous rash include fever or flu-like symptoms, with other symptoms depending on the type of rash a person has developed. An erythematous rash multiforme has raised spots on the rash’s site that have white rings surround the white spots, making the spots look like targets. With erythematous multiforme rashes, other lesions may possibly be present on the rash. Patients with erythema nodosum have raised spots which normally sit below the knees, and are sensitive to any touch. Rashes from photosensitivity appear as redness on the skin, concentrated on areas that have been exposed to direct sunlight for an extended period of time.
The causes of an erythematous rash vary, depending on the type of rash that develops. Photosensitivity rashes develop when the sun’s ultraviolet rays react with medications or infections in the person’s skin, resulting in skin irritation. With nodosum and multiforme rashes, many times the exact cause of the rash is unknown. Herpes simplex has been shown to cause erythema multiforme to develop in individuals, as does penicillin, non-steroidal anti-inflammatory medications and medications used to prevent seizures. Pregnancy, mononucleosis, taking birth control pills and lupus have all been shown to be causes of nodosum developing on an individual’s skin.
Several treatments exist for eliminating an erythematous rash, depending on the type a patient suffers from. Photosensitivity rashes require a person to stay out of sunlight as much as possible, either by staying indoors or by covering his skin whenever he goes outside. A doctor may not prescribe any treatment for a mild rash, but he might still direct a patient to use antihistamines to alleviate any itching. If the rash is the result of an infection, then the patient might need to take antibiotics, antiviral medication or aspirin to reduce the skin’s inflammation. In some extreme cases, a doctor might direct that a patient regularly expose his rashes to a diode that puts off light, engaging in what is called photomodulation therapy, which cuts down on the amount of time the rash requires to heal.