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Rash (cont.)

Rash Causes

Skin rashes have an exhaustive list of potential causes, including infections. In a broad sense, rashes are commonly categorized as infectious or noninfectious.

The following are causes of infectious rashes:


  • Trichophyton is a type of skin fungus that commonly causes rashes of the skin, hair, and nails. This infectious rash is called Tinea or "ringworm."
  • Candida can cause common yeast infections in moist areas like between the fingers, in the mouth, vaginal area, and also in the groin folds.
  • Other much less common fungal infections include cryptococcosis, aspergillosis, and histoplasmosis. These are fairly uncommon in healthy people and are more frequently seen in individuals with a compromised immune system as in HIV/AIDS and immune suppression due to cancer chemotherapy.


  • Herpes simplex (HSV) types I and II may cause infections of the lips, nose, facial skin, genitals, and buttocks.
  • Herpes zoster causes chickenpox and shingles.
  • HIV causes many types of rashes, both nonspecific viral reactions as well as infection-associated rashes.
  • Epstein-Barr virus (EBV) is associated with many types of rashes and most commonly with mononucleosis ("mono" or "kissing disease").
  • Many other viruses, including parvovirus and coxsackievirus, cause rashes. Coxsackievirus is associated with hand, foot, and mouth disease (HFMD). Young children are particularly prone to many kinds of viral infections and illnesses.


  • Staphylococcus infections are extremely common and may cause many types of rashes, including folliculitis, abscesses, furuncles, cellulitis, impetigo, staphylococcal scalded skin syndrome, and surgical wound infections.
  • Streptococcus infection may cause strep throat, scarlet fever, cellulitis, necrotizing fasciitis, and other skin infections.
  • Pseudomonas may causes all sorts of skin problems, including green discoloration of the nails, folliculitis, hot tub folliculitis, surgical wound infections, and foot infections following a penetrating injury through tennis shoes.
  • Many other types of less common bacteria cause skin rashes. These are often diagnosed by skin culture.


  • Scabies is a very itchy, contagious, superficial skin infestation with a microscopic mite.
  • Lice infestations may cause different types of itchy rashes in the affected areas like scalp and nape of the neck.

The following are causes of noninfectious rashes:

  • Drug allergies may arise from exposure to drugs containing sulfa, penicillin, antiseizure medications like phenytoin and phenobarbital, and many others.
  • Contact allergic dermatitis may develop on repeat exposure to topical products like nickel, neomycin, cobalt, fragrance, adhesives, latex, rubber, and dyes. Essentially any product may potentially induce a skin allergy.
  • Eczema or atopic dermatitis includes a wide variety of skin sensitivity in which areas of skin are dry, red, and itchy.
  • Hypersensitivity or allergic dermatitis may develop upon repeat exposure to poison oak and poison ivy.
  • Irritant dermatitis from excessive skin dryness may develop from repeat exposure to harsh soaps and cleaning chemicals.
  • Autoimmune conditions, like systemic lupus erythematosus (SLE), Hashimoto's thyroiditis, scleroderma, and other disorders in which the immune system may be overactive, often cause skin rashes.
  • Other internal diseases such as amyloidosis and sarcoidosis may cause skin symptoms and accompanying rashes.
Medically Reviewed by a Doctor on 5/30/2014

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