Contact dermatitis usually occurs on areas of your body that have been directly exposed to the substance — for example, along a calf that brushed against poison ivy or under a watchband that triggers an allergy. The reaction usually develops within minutes to hours of exposure to an irritating substance or allergen. The rash can last two to four weeks.

Signs and symptoms of contact dermatitis include:

  • Red rash or bumps
  • Itching, which may be severe
  • Dry, cracked, scaly skin, if your condition is chronic
  • Blisters, draining fluid and crusting, if your reaction is severe
  • Swelling, burning or tenderness

The severity of the rash depends on:

  • How long you're exposed
  • The strength of the substance that caused the rash
  • Environmental factors, such as temperature, airflow and sweating from wearing gloves
  • Your genetic makeup, which can affect how you respond to certain substances

When to see a doctor

See your doctor if:

  • The rash is so uncomfortable that you are losing sleep or are distracted from your daily routine
  • The rash is painful, severe or widespread
  • You're embarrassed by the way your skin looks
  • The rash doesn't get better within a few weeks
  • The rash affects your face or genitals

Seek immediate medical care in the following situations:

  • You think your skin is infected — clues include fever and pus oozing from blisters.
  • Your lungs, eyes or nasal passages are painful and inflamed, perhaps from inhaling an allergen.
  • You think the rash has damaged the mucous lining of your mouth and digestive tract.
Jul. 16, 2014

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