What should you know about Johnson's syndrome rash?

The name may refer to concern about a serious medicine-related reaction, but a rash cannot be classified safely from a name or photograph. Warning features include painful skin, rapidly spreading red or dusky areas, blisters, peeling, sores in the mouth or eyes, and feeling feverish or very unwell. Other rashes such as contact dermatitis, drug rash, infection, or psoriasis may look different and need different care.

A medicine can be relevant even when it was started recently or taken for a short time. Bring the medicine packets or a complete list, including non-prescription products and supplements. Do not delay emergency assessment while trying to identify the cause yourself.

If severe features are present, seek emergency care immediately. Avoid applying new creams, breaking blisters, or removing attached skin. Keep a record of when each medicine was started and when symptoms appeared. A treating clinician must decide which medicines should be stopped or replaced; do not restart a suspected medicine unless specifically instructed.

If the rash is mild and none of the warning signs are present, arrange prompt medical advice, especially after a new medicine. Take clear photographs and note pain, itch, fever, eye symptoms, and mouth or genital sores.

Call emergency services or attend an emergency department for skin peeling, blisters, severe skin pain, mouth or eye sores, difficulty swallowing, breathing difficulty, facial swelling, faintness, dehydration, or rapidly worsening illness. Eye symptoms deserve urgent attention because the surface of the eye can be affected.

Could any medicine or supplement have triggered this? Which products must I avoid in future? Do my eyes, mouth, or other mucosal areas need examination? What symptoms should prompt immediate return, and how should this reaction be recorded in my medical history?