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Name of Symptom/Sign:
Classifications and external resources
[[Image: |190px|center]]
A typical rash
ICD-10 R21.
ICD-9 782.1

A rash is a change in skin which affects its color, appearance, or texture. A rash may be localized to one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, dry, cracked or blistered, swell and may be painful. The causes, and therefore treatments for rashes, vary widely. Diagnosis must take into account such things as the appearance of the rash, other symptoms, what the patient may have been exposed to, occupation, and occurrence in family members.

The presence of a rash may aid associated signs and symptoms are diagnostic of certain diseases. For example, the rash in measles is an erythematous, maculopapular rash that begins a few days after the fever starts; it classically starts at the head and spreads downwards.



Common causes of rashes include:

Uncommon causes:

Evaluating a rash

The causes of a rash are extremely broad, which may make the evaluation of a rash extremely difficult. An accurate evaluation by a doctor may only be made in the context of a thorough history (What medication is the patient taking? What is the patient's occupation? Where has the patient been?) and complete physical examination.

Points to note in the examination include:

  • the appearance: e.g., purpuric (typical of vasculitis and meningococcal septiaemia), fine and like sandpaper (typical of scarlet fever); umbilicated lesions are typical of molluscum contagiosum (and in the past, small pox); plaques with silver scales are typical of psoriasis.
  • the distribution: e.g., the rash of scarlet fever becomes confluent and forms bright red lines in the skin creases of the neck, armpits and groins (Pastia's lines); the vesicles of chicken pox seem to follow the hollows of the body (they are more prominent along the depression of the spine on the back and in the hollows of both shoulder blades); very few rashes affect the palms of the hands and soles of the feet (secondary syphilis, rickettsia or spotted fevers,[1] guttate psoriasis, hand, foot and mouth disease, keratoderma blenorrhagica);
  • symmetry: e.g., herpes zoster usually only affects one side of the body and does not cross the midline.

Typically, it is never a good habit for one to scratch a rash, as doing so may invigorate the rash and cause it to spread. Gently rubbing the rash may provide temporary relief, but it is more than likely better to avoid contact with the affected areas altogether.

Quick Overview of Symptoms of Skin Rashes/Diseases

Skin Disease Symptoms Usual Area of Body
Acne Covered in small pus-filled sacs, blackheads, pimples or sore red bumps Face, Chest or Back
Rosacea Flushed appearance or Redness Around cheeks, chin, forehead or nose
Boil Painful red bump or a cluster of painful red bumps Anywhere
Cellulitis Red, tender and swollen areas of skin Around a cut, scrape or skin breach
Insect bite Red and/or itchy bumps on your skin Anywhere and can be sprinked randomly
Allergic Reaction Irregular, raised or flat red sores that appeared after taking medicine/drugs Anywhere
Hives Bumps formed suddenly Anywhere but usually first noticed on face
Seborrheic dermatitis Bumps and swelling Near glands
Cradle Cap Dry, scaly skin Cover the head of a child
Irritant contact dermatitis Red, itchy, scaly or oily rash Eyebrows, nose, edge of the scalp, point of contact with jewellery, perfume or clothing.
Allergic Contact Dermatitis caused by poison ivy, oak or sumac Red, itchy, scaly or oily rash Eyebrows, nose, edge of the scalp, point of contact with jewellery, perfume or clothing.
Allergic purpura Small red dots on your skin, or larger, bruise-like spots that appeared after taking medicine Anywhere
Pityriasis Rosea Started with a single scaly, red and slightly itchy spot, and within a few days, did large numbers of smaller patches of the rash, some red and/or others tan Chest and Abdomen
Dermatitis herpetiformis Intensely itchy rash with red bumps and blisters Elbows, knees, back or buttocks
Erythema nodosum Large red bumps that seem to bruise and are tender to touch Anywhere
Psoriasis White, Scaly rash over red, irritated skin Elbows and knees
Erythema multiforme Red, blotchy rash, with "target like" hives or sores. Anywhere
Measles Red Rash that is raised with a fever or sore throat. Usually starts first on the forehead and face and spreads downward.
Chickenpox Multiple blisters with a fever, cough, aches, tiredness and sore throat. Usually starts first on the face, chest and back and spreads downward.
Shingles Red Blisters that are very painful and may crust Anywhere
Fifth Disease Started as a fever and then developed a bright red rash Cheeks
Warts Soft bumps forming that don't itch and have no other symptoms Anywhere
Ringworm Bald spot on your scalp or a ring of itchy red skin Anywhere
Syphilis Rash that is red but not itchy Palms of hands or soles of feet
Jock Itch, Yeast Infection or Diaper rash Red itchy rash Groin
Tinea versicolor Light coloured patches Anywhere
Impetigo Crusted, tan-colored sores Near nose or lip
Scabies Bite-like sores that itch and spread intensely Usually start on hands or feet and spread everywhere
Rocky Mountain Spotted Fever A fine rash with a fever and headache Usually start on arms and legs including the hands and feet
Lupus Erythematosus A butterfly rash with achy joints Forehead and cheeks
Jaundice or sign of Hepatitis Yellowish Skin, whites of eyes and mouth
Bruise Blue or black area after being hit Anywhere
Actinic keratoses Scaly, pink, gray or tan patches or bumps Face, scalp or on the backs or your hands
Keloid or Hypertrophic scar Scar that has grown larger than expected Anywhere
Lipoma Soft or rubbery growth Anywhere
Milia Lots of white spots on the face of a baby
Molluscum or Contagiosum Small, firm, round bumps with pits in the center that may sit on tiny stalks Anywhere
Sebaceous cyst Bump with a white dome under your skin Scalp, nape of your neck or upper back
Skin Tag Soft, fleshy growth, lump or bump Face, neck, armpits or groin
Xanthelasma Yellow area under your skin Under Eyelids
Melanoma Dark bump that may have started within a mole or blemish, or, a spot or mole that has changed in color, size, shape or is painful or itchy Anywhere
Basal Cell Carcinoma Fleshy, growing mass Areas exposed to the sun
Squamous Cell Carcinoma Unusual growth that is red, scaly or crusted Face, lip or chin
Kaposi's Sarcoma Dark or black raised spots on your skin that keep growing or have appeared recently Anywhere
Erythema Annulare Centrifugum (EAC) Pink-red ring or bullseye marks Anywhere

See also


  1. ^ Boyd MA, Menon P, Graves S, Gordon DL (2007). "A febrile illness with generalized papular rash involving the palms and soles". Clin Infect Dis 44: 755–756.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Rash". A list of authors is available in Wikipedia.
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