Solar allergy impacts up to 20% of population; doctors outline symptoms, prevention and treatment

Solar allergy, also known as sun eczema, can affect up to 20 % of people. It typically appears a few hours to days after UV exposure, especially UVA, and manifests as itchy, burning papules or larger rash‑like areas on the shoulders, neck, chest or face. In some cases it presents as solar urticaria, a rapid‑onset allergic reaction: “To už se jedná o skutečnou alergickou reakci, která nastoupí velmi rychle, už do několika minut po oslnění.” Occasionally systemic symptoms such as headache, chills or nausea occur: “Někdy se přidají i celkové příznaky, jako jsou bolest hlavy, zimnice, nevolnost.”

The condition is largely genetic, with symptoms often first appearing in spring or during an initial vacation in sunny climates. Most cases resolve within one to several weeks. Prevention focuses on high‑quality broad‑spectrum sunscreens (UVA‑UVB), protective clothing with UPF ratings, and gradual desensitization through medical phototherapy (“skin hardening”), which should not be confused with tanning‑bed use. Treatment options include topical corticosteroid creams, oral steroids for more extensive reactions, antihistamines for urticaria, and, in severe cases, immunosuppressants. Emerging research explores beta‑carotene and omega‑3 supplements, though they are not yet widely recommended.