Unexplained swelling of the eyelid without any predisposing disease is frequently caused by allergies. This swelling is called angioedema. Diagnosis is by clinical examination and complete blood tests, electrolytes and renal function tests. Treatment is by antihistaminics and steroids. Take some Benadryl, but if the symptoms persist then please consult a dermatologist as oral or I/V steroids may be needed.
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