What condition is characterized by large strips of skin peeling off the feet and lower legs, leaving full thickness ulcers, and thrombocytopenia (low platelet count) or platelet clumping on a Complete Blood Count (CBC) result?

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN)

The clinical presentation of large strips of skin peeling off the feet and lower legs leaving full-thickness ulcers, combined with platelet clumping on CBC, is most consistent with Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN). 1

Key Diagnostic Features

Skin Manifestations

• Extensive epidermal detachment occurs as sheets of necrotic epidermis separate from underlying dermis, leaving exposed denuded dermis 1, 2
• The feet and lower legs are commonly involved, with prominent involvement of palms and soles being characteristic 2
• Lesional skin is extremely tender to touch, and minimal shearing forces cause the epidermis to peel back (positive Nikolsky sign) 1, 2
• Flaccid bullae develop as necrotic epidermis separates, progressing to large areas of confluent erythema in severe cases 1
• The denuded dermis exudes serum, becomes secondarily infected, and readily bleeds 1, 2

Laboratory Findings

• Platelet clumping on CBC can occur as part of the systemic inflammatory response and hematologic complications 1
• Granulocytopenia (low white blood cell count) is associated with worse prognosis 1
• Anemia and leucopenia are common sequelae of acute skin failure 1

Clinical Progression

• A prodrome of fever, malaise, and upper respiratory symptoms typically precedes the eruption by several days 1
• Cutaneous pain is a prominent early feature that should alert physicians to incipient epidermal necrolysis 1, 2
• Lesions reach maximum extent 5-7 days after disease onset 2
• Mucosal involvement of eyes, mouth, nose, and genitalia is usually an early feature, leading to erosive and hemorrhagic mucositis 1, 2

Classification by Severity

The extent of epidermal detachment determines classification and prognosis 3:

• SJS: <10% body surface area (BSA) detachment 2, 3
• SJS-TEN overlap: 10-30% BSA detachment 2, 3
• TEN: >30% BSA detachment 2, 3

Critical Immediate Actions

Urgent Referral Required

• Patients with >10% BSA epidermal loss must be admitted without delay to a burn center or ICU with experience treating SJS/TEN 1, 3
• Delayed transfer to a specialist unit is associated with increased mortality 1
• Barrier nursing in a controlled environment (25-28°C ambient temperature, pressure-relieving mattress) is essential 1

Prognostic Assessment

• Calculate SCORTEN within the first 24 hours of admission to predict mortality risk 1
• SCORTEN uses seven clinical parameters including age, BSA involvement, presence of septicemia, and granulocytopenia 1

Multidisciplinary Team Coordination

• Coordinate care through dermatology/plastic surgery, intensive care, ophthalmology, and specialist nursing 1
• Additional input may be needed from respiratory medicine, gastroenterology, gynecology, urology, oral medicine, microbiology, pain team, dietetics, and physiotherapy 1

Common Pitfalls to Avoid

Misdiagnosis Risks

• Staphylococcal scalded skin syndrome (SSSS) can mimic TEN but has absence of mucosal involvement and more superficial skin cleavage 1
• Skin biopsy or frozen section distinguishes SSSS (intraepidermal cleavage) from SJS/TEN (subepidermal cleavage) 1
• Erythema multiforme major differs by having typical targets or raised atypical targets predominantly on limbs/extremities, whereas SJS has flat atypical targets more widely distributed 1, 4

Handling Precautions

• Minimize shearing forces when moving and positioning patients, as necrotic epidermis is prone to detach 1
• Careful antishear handling techniques are essential during bedside care 1

Hematologic Monitoring

• The platelet clumping you observe may represent pseudothrombocytopenia (laboratory artifact) or true thrombocytopenia from systemic inflammation 1
• Repeat CBC with manual platelet count if clumping is suspected to be artifactual
• Monitor for progression to true granulocytopenia, which predicts worse outcomes 1

Underlying Etiology Investigation

• Document all medications (including over-the-counter preparations) taken over 2 months prior to symptom onset 1
• Most common drug triggers include allopurinol, carbamazepine, lamotrigine, nevirapine, oxicam NSAIDs, phenobarbital, phenytoin, sulfamethoxazole, and sulfasalazine 1
• In children, infection (particularly Mycoplasma pneumoniae) is more commonly the precipitant than drugs 1
• Recurrence is more common in children (up to 18% of cases) when infection is the cause 1