Stevens–Johnson syndrome Stevens–Johnson syndrome and toxic epidermal necrolysis are acute, rare, and potentially fatal skin reactions involving loss of skin and, in some cases, mucosal membranes accompanied by systemic symptoms. Medications are causative in over 80% of cases. Stevens–Johnson syndrome and toxic epidermal necrolysis are distinguished based on the extent of the detached skin surface area (Oakley & Krishnamurthy, 2022). According to High (2022), Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a disease continuum. They are distinguished chiefly by severity, based upon the percentage of body surface affected by blisters and erosions. ● SJS is the less severe condition in which skin detachment is <10% of the body surface. ● TEN involves detachment of >30% of the body surface area (BSA). ● SJS/TEN overlap describes patients with skin detachment of 10% to 30% of BSA. Medications are the leading trigger of Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in both adults and children. The risk of SJS/TEN seems to be limited to the first 8 weeks of treatment. Drugs used for a longer time are unlikely to cause SJS/TEN. The typical exposure period before reaction onset is 4 days to 4 weeks after the first continuous drug use. However, approximately 25% to 33% of cases, and probably an even higher proportion of pediatric cases, cannot be clearly attributed to a drug (High, 2022). ● The drugs that most commonly cause Stevens–Johnson syndrome/toxic epidermal necrolysis are (Oakley & Krishnamurthy, 2022): ● Anticonvulsants: Lamotrigine, carbamazepine, phenytoin, phenobarbitone ● Allopurinol, especially in doses of more than 100 mg per day ● Sulfonamides: Cotrimoxazole, sulfasalazine ● Antibiotics: Penicillins, cephalosporins, quinolones, minocycline ● Paracetamol/acetaminophen ● Nevirapine (non-nucleoside reverse-transcriptase inhibitor) ● Nonsteroidal anti-inflammatory drugs (NSAIDs): Oxicam type mainly ● Contrast media Fever, often exceeding 102.2°F (39°C), and influenza-like symptoms precede the development of mucocutaneous lesions by 1 to 3 days. Photophobia, conjunctival itching or burning, and pain with swallowing may be early symptoms of mucosal involvement. Malaise, myalgia, and arthralgia are present in most patients. In some patients, an exanthematous eruption can be the heralding sign of Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). Signs and symptoms that should alert the clinician to the possibility of SJS/TEN include fever 100.4°F (>38°C), mucositis, skin tenderness, and blistering (High, 2022). The skin lesions typically begin with ill-defined, coalescing, erythematous macules with purpuric centers, although many cases of SJS/TEN may present with diffuse erythema. The skin is often tender to the touch, and skin pain can be prominent and out of proportion to the cutaneous findings. Lesions start on the face and thorax before spreading to other areas and are symmetrically distributed. The scalp is typically spared, and palms of the hands and soles of the feet are rarely involved. Atypical target lesions with darker centers may be present. As the disease progresses, vesicles and bullae form, and within days the skin begins to slough (High, 2022). Assessment and documentation of mucous membranes along with palms of the hands and soles of feet are important with every patient who presents with complaints of fever and rash.
Figure 16. Toxic Epidermal Necrolysis
From Habif, T. (2010). Stevens-johnson-syndrome https://en.wikipedia. org/wiki/Stevens%E2%80%93Johnson_syndrome. CC BY-SA 3.0 Mucosal involvement occurs in approximately 90% of cases of SJS/TEN and can precede or follow the skin eruption (Oakley & Krishnamurthy, 2022). Painful crusts and erosions may occur on any mucosal surface. The oral mucosa and the vermilion border are almost invariably involved, with painful hemorrhagic erosions covered with a grayish-white membrane. Stomatitis and mucositis lead to impaired oral intake, with consequent malnutrition and dehydration. Ocular involvement is reported in approximately 80% of patients. The most common change in the eyes is severe conjunctivitis with purulent discharge, but bullae may develop. Corneal ulceration is frequent, and anterior uveitis or panophthalmitis may occur. Pain and photophobia are accompanying symptoms (High, 2022). Stevens–Johnson syndrome and toxic epidermal necrolysis are considered medical emergencies and require early identification and a quick referral to an acute care facility. Differential Diagnosis The differential diagnosis for Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) includes (High, 2022): ● Erythema multiforme: Erythema multiforme usually presents with typical target lesions or raised, atypical, targetoid lesions predominantly located on the extremities. Bullae and epidermal detachment are usually limited and involve less than 10% of the body surface area (BSA). In contrast, with SJS/TEN, erythema multiforme is associated with infection with herpes simplex virus in approximately 90% of cases and only rarely with drugs. ● Erythroderma and erythematous drug eruptions: The generalized and symmetric maculopapular erythema of a drug eruption can mimic early SJS/TEN. However, exanthematous drug eruptions lack mucosal involvement and the prominent skin pain of TEN. Histology shows only a mild interface dermatitis with a perivascular, inflammatory infiltrate of lymphocytes, neutrophils, and eosinophils.
EliteLearning.com/Nursing
Book Code: AUS3024
Page 51
Powered by FlippingBook