Table 1.

Factors favoring the diagnosis of AGEP over pustular psoriasis.

	AGEP	Generalized Pustular Psoriasis
History of psoriasis (family/personal)	usually lacking	often present
Distribution pattern	initially predominance in the folds	more generalized
Onset of pustules	fast (hours or few days after use of medication)	slower
Duration of pustules	Shorter (rapid resolution in a few days, max. 15 days, after drug suspension)	longer
Size of pustules	tiny (pinhead)	larger
Duration of eruption/fever	shorter (resolution in a few days after drug suspension)	longer
History of drug reaction	usual	uncommon
Recent drug administration	very frequent	less frequent
Arthritis	rare	about 30%
Histology	single-cell necrosis of keratinocytes, edema of papillary dermis, vasculitis, exocytosis of eosinophils	papillomatosis, acanthosis, tortuous or dilated vessels