The blister (vesicant) beetle can cause a dermatitis after irritant chemicals are released if the bug is crushed against the skin. If the person rubs his or her eye after crushing the bug, then periorbital or ocular complications may ensue.


Blister beetles include:

(1) Paederus (may be referred to as “Nairobi fly”)

(2) Meloidae

(3) Oedemeridae


Clinical findings may include:

(1) keratoconjunctivitis

(2) keratitis (similar to chemical burn)

(3) periorbital inflammation with or without vesicles that may be confused with cellulitis


The diagnosis is easier if there are other reasons to suspect a blister beetle:

(1) in a region where blister beetles are common

(2) skin lesions are present elsewhere

(3) the person remembers crushing a bug prior to the onset of symptoms


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