Table 1.

Demographic Information, Histopathologic Features, Special Stains and Bacillus anthracis Immunostaining Results

Case no./case definition and status*	Age/sex	Duration of illness/ treatment† (days)	Routine histopathologic examination		Bacillus anthracis immunostaining
			H&E stain	Special stains
1/Confirmed	38/F	14/9	Epidermis: mild acantholysis, mild PMN infiltrate	Negative	Cell wall: rare bacilliform, focal granular
			Dermis: edema, focal necrosis, focal hemorrhage, vasculitis, intense mononuclear perivascular infiltrate
						Capsule: focal rare granular
2/Confirmed	0.6/M	14/13	Epidermis: necrosis, hemorrhage, acantholysis, focal mild PMN infiltrate	Negative	Cell wall: focal rare bacilliform and granular
			Dermis: edema, necrosis, focal mild mononuclear perivascular infiltrate		Capsule: widespread bacilliform and granular
3/Confirmed	27/F	15/12	Epidermis: necrosis, hemorrhage, ulceration	Negative	Cell wall: focal bacilliform and granular
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense mononuclear perivascular infiltrate
						Capsule: focal bacilliform and granular
4/Confirmed	46/F	19/16	Epidermis: necrosis, hemorrhage, ulceration, PMN infiltrate	Gram stain: mixed gram-positive and gram-negative cocci	Cell wall: focal abundant bacilliform and granular
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense focal mononuclear perivascular infiltrate	Steiner’s stain: mixed cocci and bacilli
							Capsule: focal abundant bacilliform and granular
5/Confirmed	35/M	3/1	Epidermis: necrosis, hemorrhage, acantholysis, suprabasilar cleft, ulceration, mild PMN infiltrate	Gram stain: Negative	Cell wall: widespread abundant bacilliform and granular
						Steiner’s stain: abundant bacilli in dermis
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense mixed perivascular infiltrate		Capsule: widespread abundant bacilliform and granular
6/Suspect	34/M	5/3	Epidermis: necrosis, hemorrhage, acantholysis, bullous, intense PMN infiltrate	Gram stain: Negative	Cell wall: widespread abundant bacilliform and granular
						Steiner’s stain: focal bacilli in superficial dermis
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense diffuse PMN infiltrate		Capsule: widespread abundant bacilliform and granular
7/Confirmed	51/F	7/6	Epidermis: necrosis, hemorrhage, ulceration, mild focal PMN infiltrate	Gram stain: a few gram-positive bacilli in epidermis and superficial dermis	Cell wall: focal abundant bacilliform and granular
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense mixed perivascular infiltrate
					Steiner’s stain: abundant bacilli in epidermis and superficial dermis	Capsule: focal abundant bacilliform and granular
8/Confirmed	38/M	5/0	Epidermis: necrosis, suprabasillary cleft, mild PMN infiltrate, bacteria	Gram stain: abundant gram-positive bacilli in focal epidermis and superficial dermis	Cell wall: focal abundant bacilliform, less granular
			Dermis: edema, necrosis, hemorrhage, vasculitis, intense focal mononuclear perivascular infiltrate
							Capsule: focal abundant bacilliform and granular
					Steiner’s stain: abundant bacilli in focal epidermis and superficial dermis
9/Suspect	23/F	10/8	Epidermis: necrosis, acantholysis, superficial crust, mild PMN infiltrate	Negative	Negative‡
			Dermis: edema, necrosis, hemorrhage, vasculitis, moderate mixed perivascular infiltrate
10/Suspect	31/F	20/13	Epidermis: small biopsy, no significant change	Negative	Negative§
			Dermis: mild edema, mild mixed perivascular infiltrate

*Case definition and status are described in the Methods section. One suspect case was excluded because skin biopsy was unavailable for pathologic evaluation.

^†Duration of illness/antibiotic treatment prior to biopsy.

^‡Patients had multiple lesions (cheek, buttock, thigh, and lower leg); the biopsy was taken from left thigh unrelated to the primary lesion in the cheek.

^§Contained a small, superficial, shave biopsy that was inadequate for pathologic evaluation.