03 August 2026
: Case report 
Pustules in Stevens-Johnson Syndrome
Challenging differential diagnosis, Rare disease
Shunya Nagata ABEF 1*, Takaie Kuki B 1, Miyuki Kato
BE 2
DOI: 10.12659/AJCR.953161
Am J Case Rep 2026; 27:e953161
Table 2 Japanese Dermatological Association’s diagnostic criteria for Stevens-Johnson syndrome.
| Major criteria | |
| 1 | Extensive, severe mucosal lesions, such as hemorrhagic erosions with crusting, are present at mucocutaneous junctions, including the eyes, lips, and genital area |
| 2 | Generalized erythema of the skin is accompanied by erosions and blisters resulting from necrotic epidermal injury and is followed by crusting and membranous desquamation during recovery. The total area of epidermal detachment involves less than 10% of the body surface area; however, areas in which the epidermis is expected to detach easily with minimal mechanical stress are included in this estimate |
| 3 | Fever is present |
| 4 | Histopathological examination reveals necrotic changes of the epidermis* |
| 5 | Erythema multiforme [EM] major can be excluded** |
| Minor criteria | |
| 1 | The erythema is generalized and predominantly involves the face, neck, and trunk. Non-elevated, flat, atypical target lesions with a dark red center having a tendency to coalesce are observed |
| 2 | Mucosal lesions are present at the mucocutaneous junctions. Ocular involvement manifests as bilateral, acute conjunctivitis accompanied by pseudomembrane formation and/or epithelial defects of the ocular surface |
| 3 | Systemic symptoms include an objectively severe, clinical condition and subjectively reported fatigue. Oral pain and sore throat cause varying degrees of difficulty with oral intake |
| 4 | Autoimmune bullous diseases can be excluded |
| Diagnosis | SJS is diagnosed when all five major criteria are met after considering the minor findings and assessing the entire clinical course |
| Supplements | |
| 1 | Differentiation from severe erythema multiforme should be made comprehensively by considering the five major criteria (1–5) together with the severity of systemic symptoms and fatigue, response to treatment, and the extent of necrotic epidermal changes on histopathological examination |
| 2 | * Pathologically, full-thickness, epidermal necrosis may be present; however, confirmation of at least 10 necrotic keratinocytes per × 200 high-power field is recommended |
| 3 | ** EM major refers to erythema multiforme accompanied by relatively mild, mucosal involvement. The skin lesions are predominantly distributed on the extremities, and although fever is often present as a systemic symptom, the overall severity of the disease is limited. EM major is distinct from SJS |
| 4 | Stevens-Johnson syndrome can present with mucosal involvement alone |