Angioedema: a 24-hour photo diary by a patient posted on Flickr
The patient took pictures of herself and uploaded them to the photo sharing website Flickr under a Creative Commons license. She had the impression her symptoms were due to urticaria but since the process affects the subcutaneous tissues (note the upper lip edema), the more likely diagnosis is angioedema and urticaria.
Dr Heinrich Quincke first described the clinical picture of angioedema in 1882, hence the eponym Quincke's edema. Sir William Osler remarked in 1888 that some cases may have a hereditary basis; he coined the term hereditary angio-neurotic edema.
C1 protein, showing subunits C1r, C1s, and the C1q tails. Image source: Wikipedia. Patients with acquired angioedema have low C1q levels AND low C4/C2 levels. In contrast, in hereditary angioedema (HAE) the C1q level is normal.
Classical and alternative complement pathways. Image source: Wikipedia.
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
Read more about Angioedema at AllergyCases.org.
Update 8/12/2008:
Reuters features our post Angioedema: a 24-hour photo diary by a patient posted on Flickr.