A rash is a visible skin outbreak. Examples of noninfectious rashes include eczema, psoriasis, contact dermatitis, seborrheic dermatitis, rosacea, hives, and allergic dermatitis. Types of infectious rashes include ringworm, impetigo, scabies, herpes, chickenpox, and shingles. Rashes may be caused by fungi, viruses, bacteria, and parasites. Treatment depends upon the type of rash.