What should you know about cortisone injection for rash?

Cortisone injections place corticosteroid near an inflamed joint, tendon sheath, or other musculoskeletal structure. They are used for selected problems such as Ankle Osteoarthritis, Calcific Tendinitis, Carpal Tunnel Syndrome, De Quervain's Tenosynovitis, Elbow Osteoarthritis, Frozen Shoulder, Golfer's Elbow, and Hallux Rigidus. A rash may have an allergic, infectious, medication-related, or inflammatory cause, and an injection can obscure symptoms or be unsuitable.

The appearance, location, timing, itch, pain, fever, exposures, and medicines help a clinician narrow the possibilities. Avoid treating a new rash with leftover injection medicine or someone else's prescription.

Arrange an assessment if the rash is new, spreading, recurrent, painful, blistering, or unexplained. Bring a list of medicines and note new foods, products, plants, travel, or contacts. Until reviewed, use gentle fragrance-free skin care, avoid scratching, and do not apply a steroid product to broken or infected-looking skin unless a clinician has advised it.

If a clinician has recommended an injection for a separate orthopaedic condition, explain the rash before treatment. The rash may need a separate diagnosis and plan.

Seek urgent help for a rash with trouble breathing, swelling of the lips or tongue, faintness, rapidly spreading hives, blistering, skin peeling, or involvement of the eyes or mouth. Same-day assessment is sensible when rash comes with fever, severe pain, pus, marked warmth, or rapid spread. These features can signal a reaction or infection rather than a routine musculoskeletal problem.

What is the likely cause of this rash? Does it need a skin examination or testing? Could any current medicine or product be responsible? Is the planned cortisone injection for a separate condition safe to continue, and what warning signs should I watch for?