Table 2. Differential diagnosis of ANUG.

ANUG: acute necrotizing ulcerative gingivitis; HSV: herpes simplex virus 

ANUG	Primary herpetic gingivostomatitis	Desquamative gingivitis	Chronic destructive periodontal disease	Diphtheria
Fusospirochetal complex	HSV	Few bacterial forms	Variable bacterial smears	Corynebacterium diphtheria
Punched-out necrosed papilla and marginal gingiva	Gingiva (diffused) buccal mucosa and lips	Gingiva and mucosa	Marginal gingiva	Marginal gingiva (rarely)
Pseudomembranous epithelium	Diffuse erythema and vesicular eruption	Patchy desquamation	No desquamation, but purulent material may appear from pockets	Membrane removal difficult
Adults and adolescents	Children	Adults and Women	Adults