Sun allergy in black skin: what to know

Polymorphic light eruption is a delayed skin reaction that may appear after sunlight reaches exposed areas. On deeply pigmented skin, redness can be less obvious; itching, raised bumps, small blisters, tenderness, or a change in skin colour may be easier to notice. The rash can occur on the arms, chest, neck, or face and may settle when exposure stops. Darker marks can remain after the active irritation fades. A clinician may consider other causes, including contact reactions, eczema, medication sensitivity, or heat-related rash, before confirming the diagnosis.

Reduce direct sun while the skin is active. Use shade, tightly woven clothing, a broad-brimmed hat, and a broad-spectrum sunscreen that you can tolerate; reapply as directed, especially after sweating or washing. Avoid introducing several fragranced products at once, because irritation can make the pattern harder to interpret. Take a clear photograph when the rash is visible and record recent medicines, skincare products, and the timing of exposure. A dermatologist may discuss a short course of prescribed topical corticosteroids for inflammation or supervised narrowband UVB phototherapy to build tolerance in selected recurrent cases.

Arrange a clinical review if the eruption keeps returning, spreads beyond sun-exposed skin, leaves persistent colour change, or does not improve after avoiding light. Seek urgent help for facial swelling with breathing difficulty, widespread blistering, skin peeling, fever, eye involvement, or painful sores. Do not apply a strong steroid, bleaching product, or unlabelled remedy to pigmented skin without professional advice.

Ask whether the pattern fits polymorphic light eruption, whether any medicine or product could be contributing, and how to prevent post-inflammatory darkening. You can also ask which sunscreen texture suits your skin, how long a prescribed topical treatment should be used, and whether phototherapy is appropriate.