Autoimmune Angioedema

Autoimmune angioedema is a rare condition where the immune system mistakenly triggers swelling in the deeper layers of the skin or mucous membranes. In autoimmune angioedema, the immune system may interfere with a protein called C1 inhibitor, leading to abnormal activation of the body's inflammatory pathways.

Sudden swelling in the face, lips, eyelids, hands, feet, or genitals; Swelling of the tongue or throat which can be dangerous; Abdominal pain, cramping, nausea, or vomiting (if swelling occurs in the gut); No hives or rash unlike typical allergic reactions; Episodes can last for hours to days and may come and go over time.

Not caused by allergies. The body makes autoantibodies that interfere with C1 inhibitor, a protein that controls inflammation. May be linked to other autoimmune diseases like Lupus (SLE), Rheumatoid arthritis, or Hashimoto's thyroiditis.

C1 inhibitor (C1-INH) levels and function; C4 complement levels (often low during attacks); ANA or other autoimmune antibody tests; Detailed history of episodes to rule out allergies or medications like ACE inhibitors.

C1 inhibitor replacement therapy (for those with low levels); Immunosuppressants or corticosteroids to calm the immune system; Antihistamines or epinephrine (less effective unless histamine is involved); Fresh frozen plasma in emergency settings; Emergency treatment may include airway management if breathing is affected.

Many people manage it well with treatment and lifestyle adjustments. Swelling can be unpredictable, and severe episodes (especially in the throat) are medical emergencies. Ongoing care and monitoring for other autoimmune conditions is often needed.

Very rare - estimated fewer than 1 in 50,000 people. May be underdiagnosed especially when symptoms are mistaken for allergies. Affects both men and women, often diagnosed in adulthood.