Target lesion

Target lesion in dermatology is the typical lesion of erythema multiforme (EM) in which a vesicle is surrounded by an often hemorrhagic maculopapule; EM is often self-limited, of acute onset, resolves in three to six weeks, and has a cyclical pattern; EM lesions are 'multiform' and include macules, papules, vesicles, bullae. Etiology Idiopathic or follow infections, drug therapy or occur in immunocompromised hosts

Morphology

Target lesion consists of three zones :

1. Dark centre of small papule, vesicle, or bulla (iris)
2. Pale intermediate zone
3. Peripheral rim of erythema

References

the free dictionary : medical dictionary [1]