Angioedema is inflammation of the deep dermis or submucosa. It can be life threatening if it involves the airway. It can be congenital, idiopathic, or drug induced. Ace inhibitor blood pressure medications are common offenders causing this condition. Food allergies are another big culprit. A thorough allergy history and testing are paramount. Exciting new drugs are on the horizon for this condition.
Congenital or Hereditary Angioedema is relatively rare. It is essentially caused from either absent of non functioning complement factors. Primarily C1 Esterase Inhibitor. Acquired or hereditary angioedema do not typically respond to antihistamines or steroids, so the fact that he got better with these medications argues against this. Also, Hereditary Angioedema does not Urticate (No Hives). Nevertheless, checking labs would put these (remote) possibilities to rest. A good laboratory screen would be aC2, C3, C4, C1q, and C1-INH level and function, ESR, ANA, RF, hepatic transaminases, TSH, T4, anti-thyroglobulin antibodies, anti-thyroid peroxidase antibodies, CBC/diff and CU index (available thru Quest and Labcorp).
The vast majority of Angioedema is idiopathic and often drug induced. It is essentially a deeper (subdermal or submucosal) version of urticaria and is similarly most often idiopathic. Medications started within the past several months are most likely. However, ACE inhibitors are notorious for causing these reactions even after years of safe use. Aspirin and NSAIDs are also frequent causes or exacerbating factors. Less commonly, underlying problems like thyroid disease, liver disease, autoimmune disease or occult malignancy can be responsible. About half of patients with otherwise “idiopathic” chronic urticaria/angioedema make IgG autoantibodies against the high affinity IgE receptor on mast cells. Foods are uncommon offenders, but should be considered. Routine allergy testing and diet diary are appropriate.
Treatment is largely symptomatic. Symptoms wax and wane for weeks and even months. Unfortunately up to 95% of patients will never find the etiology. I often suggest a daily 24 hour acting antihistamine to prevent/suppress episodes, such as Zyrtec 10 mg qd. If symptoms persist, you can add Allegra 180 mg qam and take Zyrtec 10 mg qhs. If symptoms STILL persist, you can continue Allegra and switch Zyrtec to Atarax, titrated as needed to suppress episodes while minimizing (hopefully) daytime sedation. I also often add a type 2 antihistamine such as Zantac. Steroids of course are helpful, however one should be cautious of rebound inflammation.