PANCE Blueprint Dermatology (5%)

Patient will present as → a 60-year-old woman with a severe drug-induced reaction on both lower limbs with few lesions elsewhere in addition to mucosal involvement of the mouth of two days duration. The insulting drug was sulfonamide, and the onset of the rash was within 48 hours of taking the drug. The rash is comprised of bilateral symmetrical bullae on a background of erythematous macules and patches in addition to erosions and peeling.

Stevens-Johnson syndrome (SJS) is a milder form of toxic epidermal necrolysis (TEN) with LESS THAN 10% of body surface area detachment

• Stevens-Johnson syndrome, toxic epidermal necrolysis, and SJS/TEN overlap. All three are part of a spectrum of severe cutaneous reactions (SCAR) which affect the skin and mucous membranes

The distinction between SJS, SJS/TEN overlap, and TEN is based on the type of lesions and the amount of the body surface area with blisters and erosions

1. Blisters and erosions cover between 3% and 10% of the body in SJS
2. 11–30% in SJS/TEN overlap
3. over 30% in TEN

• Severe, potentially fatal, mucocutaneous drug reactions characterized by epidermal necrosis involving skin and at least 2 mucous membranes
• Most common with drug eruptions: Over 100 medications have been implicated in causing SJS especially sulfa and anticonvulsant medications
• Prodromal period for 1–7 days of low-grade fever, sore throat or upper respiratory infection or dysphagia, and general malaise; the patient may also complain of pain or stinging in the eyes
• Subsequent development of targetoid red papules and plaques with dusky, blistered, or eroded center as well as mucosal (lip, intraoral, conjunctival, urethral, anal) pain with blistering and erosions.
• The progression of the disease to sheets of widespread epidermal necrosis and sloughing may be hours. This is a medical emergency.
• Eye symptoms may be severe
• (+) Nikolsky's sign: skin peels away in sheets when pressure applied and rubbed.

Clinical evaluation and skin biopsy  - shows necrotic epithelium

• If the test is available, elevated levels of serum granulysin taken in the first few days of a drug eruption may be predictive of SJS/TEN.
• Diagnosis is often obvious from the appearance of lesions and rapid progression of symptoms. Histologic examination of sloughed skin shows necrotic epithelium, a distinguishing feature.
• Differential diagnosis in SJS and early TEN include erythema multiforme, viral exanthems, and other drug rashes; SJS/TEN can usually be differentiated clinically as the disorder evolves and is characterized by significant pain and skin sloughing.

Mortality prediction scoring: 

SCORTEN Scale

SCORTEN is an illness severity score that has been developed to predict mortality in SJS and TEN cases. One point is scored for each of the seven criteria present at the time of admission. The SCORTEN criteria are:

ABCD 10 Mortality prediction model score

A: Age over 50 years (one point) B: Bicarbonate level < 20 mmol/L (one point) C: Cancer present and active (two points) D: Dialysis prior to admission (3 points) 10: Epidermal detachment ≥ 10% of body surface area on admission (one point)

Stop all potentially offending medications

• Early admission to burn unit or pediatric intensive care unit for initial stabilization and management of fluid, electrolytes, and nutrition; airway stability; and eye care
• Prompt ophthalmology and dermatology consultation
• Intravenous immunoglobulin (IVIG)
• Steroids used to be the treatment of choice are now thought to be an increased risk for sepsis

Stevens-Johnson syndrome

Image by Balasundaram S, Ranganathan K, Umadevi K, Gunaseelan R, Kumaraswamy N, Solomon S, Devaleenol B, Ambrose P – Journal of oral and maxillofacial pathology. CC BY 2.0

Image: by lasundaram S, Ranganathan K, Umadevi K, Gunaseelan R, Kumaraswamy N, Solomon S, Devaleenol B, Ambrose P – Journal of oral and maxillofacial pathology: JOMFP (2011). CC BY 2.0

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