What are the typical symptoms of Stevens-Johnson syndrome?

Most Likely Symptoms of Stevens-Johnson Syndrome

Stevens-Johnson syndrome presents with a characteristic triad: painful skin lesions with purpuric macules or flat atypical targets, severe mucous membrane involvement (eyes, mouth, nose, genitalia), and a preceding prodrome of fever and malaise, typically occurring 4-28 days after drug exposure. 1, 2

Prodromal Phase (Precedes Skin Eruption by Several Days)

• Fever and malaise are prominent early features 1, 3
• Upper respiratory tract symptoms resembling "flu-like" illness 1, 3
• Cutaneous pain is a critical early warning sign that should immediately alert physicians to incipient epidermal necrolysis 1, 2
• Ocular inflammation may develop before skin signs appear 1

Cutaneous Manifestations

Initial Lesion Characteristics

• Earliest lesions appear as atypical targets and/or purpuric macules (dark red, flat lesions) 1, 2
• Lesions are characterized by a dark red center surrounded by a pink ring 1, 2
• Initial distribution: upper torso, proximal limbs, and face, then spreading to trunk and distal limbs 1, 2
• Palms and soles involvement is often prominent 1, 2

Progression Pattern

• Lesions expand and coalesce, reaching maximum extent 5-7 days after disease onset 1, 2
• Large areas of confluent erythema develop in severe cases 1, 2
• Lesional skin is exquisitely tender to touch 1, 2
• Positive Nikolsky sign: minimal shearing forces or gentle lateral pressure causes epidermis to peel back 1, 2

Advanced Skin Findings

• Flaccid blisters develop as necrotic epidermis separates from underlying dermis 1, 2, 4
• Extensive necrolysis results in detachment of sheets of epidermis, leaving exposed, denuded dermis 1, 2
• Denuded dermis exudes serum, becomes secondarily infected, and readily bleeds 1, 2

Mucous Membrane Involvement (Usually an Early Feature)

• Erosive and hemorrhagic mucositis affecting multiple sites 1, 2, 5
• Ocular involvement: purulent keratoconjunctivitis with eyelid edema develops early 5
• Oral mucositis: mucosal erythema, blistering, and painful erosions that may require nasogastric tube feeding 1, 5
• Genital and nasal mucosa involvement with erosions 1, 2
• In some cases (particularly Mycoplasma-associated), predominantly mucous membrane involvement with minimal cutaneous lesions may occur 1, 2

Classification by Extent of Epidermal Detachment

• SJS: <10% body surface area (BSA) detachment plus widespread purpuric macules or flat atypical targets 1, 2
• SJS-TEN overlap: 10-30% BSA detachment plus widespread purpuric macules or flat atypical targets 1, 2
• TEN: >30% BSA detachment 1, 2

Critical Clinical Pitfalls

• Cutaneous pain preceding visible skin changes is a red flag that demands immediate evaluation 1, 2
• The Nikolsky sign is helpful but not specific for SJS/TEN (also positive in pemphigus) 1, 2
• Differentiation from erythema multiforme major is crucial: EMM has typical raised targets predominantly on limbs/extremities, while SJS has flat atypical targets more widely distributed 1
• Document both extent of erythema AND epidermal detachment (detachable epidermis appears as dusky erythema before frank blistering) 1
• Symptoms typically begin 4-28 days after drug initiation, which is critical for identifying the culprit medication 6, 3, 4