Table 1 Helpful historical clues
HistoryCellulitisAllergic contact dermatitisErythema nodosumPapular urticaria
Is or was the rash itchy?NegativePositiveNegativePositive
Is the patient febrile?Sometimes positiveNegativeSometimes positiveNegative (in all but the rarest cases)
Woods/outdoors exposure recently?NegativePositiveNegativePositive
Portal of entry or punctum?Sometimes positiveNegativeNegativeSometimes positive