Table 2 Helpful physical exam and laboratory clues

Physical/laboratory	Cellulitis	Allergic contact dermatitis	Erythema nodosum	Papular urticaria
Bilateral or multifocal?	Negative	Frequently positive	Positive	Frequently positive
Exquisitely tender to palpation?	Positive	Negative	Positive	Negative
Linear lesions?	Negative	Frequently positive	Negative	Negative
Lymphangitic spread?	Sometimes positive	Negative	Negative	Negative
Elevated white blood cell count?	Sometimes positive	Negative	Sometimes positive	Negative