Introduction
Isolated solar angioedema(ISA) is a type of angioedema that is evoked upon hours of sun exposure. It may preceded with stinging pain or burning sensation. It mainly affects female patients. Oral contraceptive pills may play a role. No systemic manifestations have been detected. Treatment options of isloated solar angioedema mainly include prednisone, antihistamines and phototherapy. Some authors consider ISA as a variant of solar urticaria.
Types of isolated solar angioedema
- Mast cell-mediated angioedema : it is associated mostly with urticaria and improves on antihistamines.
- Bradykinin-mediated angioedema: urticarial lesions are not seen with types. It shows poor response to antihistamines and corticosteroids but it hsow some improvement on epinephrine.
How to suspect isolated solar angioedema
If you have a patient presented with angioedema on sun exposed site
- Ask about recent exposure to sun light.
- History of use any topical products to exclude allergic photocontact dermatitis.
- Examine the skin to exclude solar urticaria in case of the pateint has wheals associated with angioedema.
- Exclude other causes of isolated angioedema
- Low C4, C1 esterase inhibitor level and posisitive family history may point to hereditary angioedema.
- Drug history ( ACEI – NSAIDS) may point to drug induced angioedema.
- Test for porphyrins to exculde porphyria.
- Test for ANA , Anti-Ro , Anti-La to exclude collagen vascular diseases.
- History of exposure to sun light and photoprovocation testing usually supports diagnosis of isolated solar angioedema.
Treatment options of isolated solar angioedema
Instructions
- Avdise your patient to avoid sun exposure.
- Photoprotection with broadspectrum high factor sunblock.
- Application of UV blocking film to the windows of home and cars.
Medical treatment options of isolated solar angioedema
- Acute episodes
- Prednisone 40 mg daily.
- Prophylaxis
- Cetirizine 20 mg once daily.
- Phototherapy.
References:
Solar angioedema: an uncommonly recognized condition?
Isolated solar angioedema: A systematic review of the literature