Angioedema in Infant/Neonate
There are 3 mechanisms thought to be responsible:
- IgE mediated – IgE sensitizes mast cells to release vasoactive substance. Seen with reaction to antibiotics or radiocontrast.
- Complement mediated – The activated complement causes anaphylotoxin release, which causes mast cell degranulation. Seen with whole blood or immunoglobulin infusions.
- Immune complex mediated – Immune complexes cause mast cell degranulation. Seen in 1/10 000 courses of penicillin.
Tick bites from some Amblyomma and Ixodes (and possibly Haemaphysalis) species have been associated with the subsequent development of allergies to mammalian meat (eg, beef, pork) in a small number of patients. It is thought that the allergy is mediated by induced IgE antibodies to alpha-gal (galactose-alpha-1,3-galactose), a mammalian oligosaccharide. Individuals with elevated IgE titers to alpha-gal have experienced urticaria, angioedema, and anaphylaxis symptoms either immediately or 3-6 hours (delayed onset) after ingesting mammalian meat. Exactly how the tick bite leads to development of this allergy is unclear. Implicated tick bites have been noted to itch for 2 or more weeks. A blood test for these IgE antibodies exists.
Idiopathic angioedema is 3 or more episodes of recurrent angioedema with no apparent cause after comprehensive medical evaluation.
Nonhistaminergic angioedema, which occurs in about 1 of 20 cases, does not present with hives, unlike allergic and idiopathic forms of angioedema. Similar to hereditary angioedema and to ACE inhibitor-induced angioedema, where there is bradykinin involvement, nonhistaminergic angioedema is not responsive to antihistamines or corticosteroids.
Angioedema seen in the heritable angioedema syndrome lasts longer, is not responsive to standard antihistamine therapy, and usually will not have typical urticarial lesions. Familial forms begin in adolescence; they have autosomal dominant inheritance and are related to disorders of complement regulation. Episodes of angioedema are often precipitated by surgery or accidents. There are symptoms, such as abdominal pain, that are not a feature of typical angioedema.
T78.3XXA – Angioneurotic edema, initial encounter
41291007 – Angioedema