Table 7 Diagnostic criteria for photodistributed Steven’s–Johnson syndrome and toxic epidermal necrolysis

Must identify = need all 4:

   1. A photodistributed rash as a result of UVR exposure after drug initiation (or other known SJS/TEN cause)

   2. Rash progression/worsening > 48 h to include vesicles/bullae and/or sloughing of the epidermis

   3. Negative direct immunofluorescence

   4. More likely SJS/TEN than erythema multiforme

Major criteria (should identify) = need 3/4:

   1. A causal drug

   2. Mucous membrane involvement

   3. Positive Nikolsky sign

   4. Histopathology demonstrating full-thickness epidermal necrosis with subepidermal bullae development

Minor criteria (common findings) = need 2/4:

   1. Palmar and plantar rash

   2. Delayed rash onset that presents no earlier than the day after UVR exposure

   3. Satellite lesions/non-discrete borders on UVR protected (clothing covered) skin

   4. No flu-like prodrome