What should you know about sarcoidosis and skin rash?

A sarcoid rash may consist of firm, smooth bumps, plaques, or changes in skin colour. It can appear on the face, scars, tattoos, limbs, or other areas, and it may or may not itch. The appearance can vary with skin tone and the depth of inflammation.

Other rashes can look similar. Atopic Dermatitis and Contact Dermatitis may itch and become inflamed; Drug Rash may follow a new medicine; Heat Rash appears in sweaty or covered areas; and Intertrigo affects skin folds. Psoriasis, Ringworm, and Scabies each have patterns that require different treatment.

Arrange a skin assessment if the rash persists, spreads, returns, or changes after a medicine. Record its start date, symptoms, body sites, recent products, illnesses, travel, and medication changes. Take clear photographs in consistent lighting if the rash changes before the appointment.

Avoid starting several new creams at once, because this can irritate the skin and obscure the pattern. A clinician may use examination and, when needed, a scraping, swab, blood test, or biopsy to identify the cause and choose treatment.

Seek prompt medical care for a painful, blistering, ulcerated, rapidly spreading, or infected-looking rash, or for a rash with fever or marked illness. Get urgent help for facial swelling, breathing difficulty, skin peeling, mouth or eye involvement, or faintness after a medicine.

Does this rash resemble cutaneous sarcoidosis or another condition? Could a medicine, infection, heat, or contact exposure explain it? Would testing or biopsy help? Should my sarcoidosis follow-up change, and which skin products are safe while the diagnosis is being clarified?