Stevens-Johnson Syndrome: A Severe Mucocutaneous Reaction
Stevens-Johnson Syndrome (SJS) is a rare, severe mucocutaneous reaction characterized by blistering and epithelial sloughing of skin and mucous membranes, usually triggered by medications or infections, with potentially life-threatening complications and long-term sequelae. 1
Clinical Presentation
Prodromal Phase
- Fever, malaise, and upper respiratory tract symptoms typically precede the eruption by several days 2, 1
- Cutaneous pain is a prominent early feature that should alert clinicians to incipient epidermal necrolysis 2
- Ocular inflammation may develop before skin manifestations 2
Cutaneous and Mucosal Manifestations
- Initial lesions present as atypical targets and/or purpuric macules, commonly starting on the upper torso, proximal limbs, and face 2, 1
- Progressive spread to trunk and distal limbs, often involving palms and soles 1
- Mucosal involvement is early and prominent, leading to erosive and hemorrhagic mucositis affecting:
- Eyes
- Mouth
- Nose
- Genitalia 1
Classification by Severity
| Syndrome | Body Surface Area Involvement |
|---|---|
| SJS | <10% |
| SJS/TEN overlap | 10-30% |
| TEN | >30% |
Etiology
Medications
- Most common triggers include:
- Anti-infective sulfonamides
- Anti-epileptic drugs
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Allopurinol 3
- New drugs, particularly anti-cancer medications, must also be considered 2
Infections
- Common in the pediatric population (up to 50% of cases) 2
- Key infectious triggers:
- Herpes simplex virus
- Mycoplasma pneumoniae
- Chlamydia pneumoniae 2
Pathophysiology
- Characterized by widespread epithelial keratinocyte apoptosis and necrosis 2
- Process initiated by drug-induced cytotoxic T lymphocytes (CTLs) 2
- Granulysin is considered the key mediator of apoptosis in SJS/TEN 2
- Genetic predisposition exists in certain populations (e.g., HLA-B*1502 in South East Asians taking carbamazepine) 2
Diagnosis
- Primarily clinical, based on characteristic presentation with skin and mucosal involvement 1
- Skin biopsy shows:
- Variable epidermal damage ranging from individual cell apoptosis to confluent epidermal necrosis
- Basal cell vacuolar degeneration
- Subepidermal vesicle or bulla formation
- Mild perivascular infiltrate of lymphocytes and histiocytes 1
Differential Diagnosis
- Staphylococcal Scalded Skin Syndrome (SSSS)
- Erythema Multiforme Major (EMM)
- Immunobullous disorders (pemphigus, pemphigoid) 1
- Atypical presentations with isolated mucosal involvement can be diagnostically challenging 4
Management
Immediate Interventions
- Stop any suspected culprit drug immediately 1
- Refer to a specialized center with experience in managing SJS/TEN 1, 5
- Burns unit or specialized dermatology service with intensive care capabilities
- Early transfer is crucial as delay adversely affects outcomes 2
Supportive Care (Cornerstone of Management)
- Fluid and electrolyte management
- Wound care
- Nutritional support
- Pain management 1
- Monitoring for and treatment of sepsis, which is a leading cause of mortality 3
Specific Treatments
- Systemic corticosteroids
- Cyclosporine A
- TNF-α inhibitors
- Immunoglobulins 3, 6
- For infection-triggered SJS, appropriate antimicrobial therapy (e.g., acyclovir for herpes infections) 1
Prognosis and Complications
- Mortality rates: <10% for SJS, rising to 30% for TEN 2, 1
- Acute complications include sepsis and multiorgan failure 1
- Long-term sequelae affect:
- Skin (pigmentation changes, scarring)
- Eyes (vision impairment)
- Mucous membranes (oral, dental, respiratory, and urogenital problems) 1
Special Considerations
- Recurrence is more common in children (up to 18% of cases), particularly when triggered by infections 1
- Prophylactic strategies for recurrent HSV-associated SJS include continuous low-dose acyclovir 1
- Genetic testing for HLA associations may be appropriate in certain populations before prescribing high-risk medications 2