Basics

What Is Skin Rash?

A rash is a noticeable change in the skin’s color, texture, or appearance. It may present as redness, bumps, blisters, or patches of irritated skin. Rashes can be itchy, painful, or asymptomatic. They may be caused by temporary irritation or reflect underlying infections, allergies, or chronic conditions.

Causes and Risk Factors of Skin Rash

  • Allergic reactions: Foods, medications, insect bites, contact with plants (poison ivy).
  • Infections: Viral (measles, chickenpox), bacterial (impetigo, cellulitis), fungal (ringworm, yeast).
  • Chronic skin diseases: Eczema, psoriasis, rosacea.
  • Environmental factors: Heat, humidity, sweating, irritant exposure.
  • Risk factors: Family history of allergies or eczema, weakened immune system, outdoor activities, new medications or skin products.

When to Seek Medical Care

Seek immediate help if a rash is widespread, painful, or associated with fever, swelling, shortness of breath, or swelling of the face and lips (signs of severe allergic reaction). See a doctor if the rash persists longer than two weeks, spreads rapidly, or shows signs of infection such as pus, warmth, or pain.