A rash is any change in the skin's color, texture, or feel, and most rashes fall into a handful of patterns a dermatologist can recognize on sight: eczema, contact dermatitis, psoriasis, hives, fungal infection, drug eruptions, rosacea, and viral rashes among them. Persistent redness on the face is most often rosacea or seborrheic dermatitis; a rash that itches at night is often eczema or scabies; a rash that appeared after a new medication needs prompt evaluation. Getting the right name for the rash is what makes treatment work.

What causes a rash?

Irritation or allergy to something touching the skin, inflammatory conditions like eczema and psoriasis, infections (fungal, bacterial, viral), reactions to medications, autoimmune disease, and heat or sun. Timing, location, and whether the rash itches, burns, or hurts narrow the list quickly.

When is a rash serious?

A rash with fever, blistering, peeling, mouth sores, or that spreads quickly over hours needs urgent care. A rash that began within weeks of starting a new medication should be evaluated promptly. Redness that is warm, swollen, and painful can be a skin infection.

How is a rash diagnosed and treated?

Most rashes are diagnosed by examination and history. When the diagnosis is unclear, a small skin biopsy or a patch test for allergies gives a definitive answer. Treatment ranges from topical steroids and moisturizers to antifungals, antihistamines, or systemic therapy for inflammatory disease. Stopping the trigger, when there is one, is half the cure.

How Tono treats rashes and redness

Tono's board-certified dermatologists see patients with a rash within days, not months, by video visit in 33 states and in person at Tono clinical centers. Photographs work well for rashes: our platform captures the images and history a dermatologist needs, and most rashes are diagnosed on the first video visit. When a biopsy or patch test is needed, we arrange it at a Tono center or near you. Your visit ends with a written plan, prescriptions sent to your pharmacy, and follow-up scheduled with the same dermatologist. Most insurance is accepted and no referral is required.

When should I see a dermatologist for a rash?

See a dermatologist if a rash has lasted more than two weeks, keeps coming back, is spreading, interferes with sleep, or has not responded to over-the-counter treatment. Seek same-day care for fever, blisters, or rapid spread.