Solar Angioedema - Local Angioedema Following Sun Exposure

Angioedema is a hereditary or acquired disease characterized by localized non-pitting swelling of the subcutaneous tissue which can affect either skin or mucous membranes.

Acquired angioedema can often be related to a heterogeneous group of factors including physical stimuli, although up to 38% of cases remain idiopathic.

This Italian study describes 5 patients who developed an angioedema following sun exposures. All patients reported an intensely stinging angioedema strictly limited to face and extremities, when exposed to solar light. Urticarial wheals were never observed or reported by patients, and oral antihistamines proved to be of no help in preventing or improving the condition of lesions.

Laboratory and phototesting data ruled out other acquired or inherited diseases characterized by photosensitivity. According to the authors, solar angioedema should be considered a novel clinical entity.

Angioedema (AE) can be allergic or non-allergic.

There are 5 types of non-allergic angioedema (AE):

- acquired AE
- hereditary AE (HAE)
- ACE-inhibitor induced AE
- idiopathic AE, can occur with chronic urticaria
- pseudoallergic AE, e.g. reaction to NSAIDs

There are 3 types of HAE that are differentiated by C4 and C1-INH levels

- type I HAE - low C4, low C1-INH function, low C1-INH antigen level
- type II HAE - low C4, low C1-INH function, normal C1-INH antigen level
- type III HAE - all normal

Treatment of acute HAE attacks

- C1-INH, 20 units/kg, IV infusion
- Icatibant, 30 mg SC, bradykinin B2 receptor antagonist
- Ecallantide, 30 mg SC, kallikrein receptor antagonist

Prophylaxis of HAE attacks

- C1-INH, 1,000 units, IV infusion every 3-4 days
- attenuated androgen, e.g. danocrine 200 mg PO TID

References:

Local Angioedema following Sun Exposures: A Report of Five Cases. Calzavara-Pinton P, Sala R, Venturini M, Rossi MT, Tosoni C, Lodi Rizzini F, Zane C. Int Arch Allergy Immunol. 2010 May 20;153(3):315-320.
New Directions in the Treatment of Angioedema. Medscape, 2012.
What are treatment options for idiopathic angioedema? Some success with HAE therapies, omalizumab, tranexamic acid http://buff.ly/1JH09Pm
Image source: OpenClipArt.org, public domain.