When to worry about a skin rash with contact dermatitis

Contact dermatitis can cause redness, itching, burning, swelling, scaling, or small blisters where skin touched an irritant or allergen. The affected area may extend beyond the exact contact zone, particularly after an allergic reaction. Weeping, pus, yellow crust, warmth, increasing pain, or red streaking can point to infection. Swelling of the lips, tongue, eyelids, or throat is a different level of concern and can accompany a serious allergic reaction.

Stop using the suspected product if doing so is safe, rinse exposed skin gently, and remove contaminated clothing or jewellery. Avoid rubbing, fragranced creams, and repeated washing that dries the skin. Keep a list of products, workplace exposures, plants, metals, and medicines that preceded the reaction. Do not deliberately reapply a suspected trigger to test it. A pharmacist or clinician can help choose a suitable soothing treatment and decide whether patch testing is useful.

Contact a clinician if the rash continues to spread after exposure stops, repeatedly returns, interferes with sleep, or involves the face, genitals, hands, or a large area. Seek urgent help for breathing trouble, throat tightness, faintness, sudden facial swelling, widespread blistering, severe pain, fever, pus, or rapidly worsening redness. These signs may require treatment beyond simple trigger avoidance.

Which exposure is most likely to be responsible? Do I need patch testing? What can I safely use on the affected area? How should I handle future workplace or product exposure?