A rash is a general term for inflammation of the skin. Rashes may be caused by many things including, but not limited to, autoimmune disease, infections, allergic contact dermatitis or irritant contact dermatitis, medications, and occasionally skin cancer.
Causes of Rashes
Bacteria, fungi, and viruses can all affect the skin and may cause infection, which can cause a rash as well. Bacterial diseases generally appear as tender crusted areas, pustules, or in ring-like patches. Other common causes of rashes are fungal diseases, such as ringworm or athlete’s foot.
Viral diseases can cause rashes, either directly as in herpes, chicken pox and shingles, or indirectly as a rash appearing during a viral illness, such as roseola.
Any medication can potentially cause a rash to develop in someone. Common medications that cause a rash include antibiotics and medications for high blood pressure and cholesterol.
Rarely, skin cancer can look like a rash. Superficial skin cancers, such as basal cell or squamous cell carcinoma, can present as scaly pink patches. Lymphoma of the skin can present as a scaly rash on the body.
Because many rashes look similar, it is important to consult a dermatologist when you have a rash that is not going away or that you are concerned about for any reason.
Other conditions with rashes include Allergic contact dermatitis (such as poison ivy), psoriasis, erythema migrans (Lyme disease), and herpes zoster (shingles).