Solar Urticaria: Understanding Sun Allergies, Symptoms & Management

Solar urticaria is a rare, chronic photosensitivity disorder where exposure to ultraviolet (UV) or sometimes visible light triggers an allergic skin reaction. It is a type of physical urticaria (hives).

Symptoms

• Hives (wheals): Red, itchy, raised welts appearing within minutes of sun exposure.
• Intense itching (pruritus), burning, or stinging.
• Redness (erythema) and swelling (angioedema) of exposed skin.
• Symptoms typically resolve within hours after avoiding light.
• Severe cases: Systemic symptoms—headache, nausea, syncope, bronchospasm, or anaphylaxis (life-threatening).

Triggers

• UVA (320–400 nm) most common, but UVB and visible light can also trigger reactions.
• Reaction threshold varies; some react to brief exposure.

Management

Photoprotection: Broad-spectrum sunscreen (high UVA protection), protective clothing, wide-brim hats, UV-blocking window films.
Medications: Second-generation antihistamines (cetirizine, loratadine, fexofenadine) first-line; higher doses sometimes used. Leukotriene antagonists, omalizumab (anti-IgE) for refractory cases.
Phototherapy (Photohardening): Gradual, controlled UV exposure in spring to induce tolerance.
Immunosuppressants: Cyclosporine for severe, unresponsive cases.
Emergency: Epinephrine auto-injector for anaphylaxis risk.

Note: No cure exists, but symptoms can be effectively managed with a tailored plan from a dermatologist or allergist.