Disease Description (Causes and Symptoms)
- Definition: An acute inflammatory disease involving severe systemic skin and mucosal disease, epidermal detachment (blistering and sloughing), and extensive mucosal involvement (Stevens–Johnson syndrome; SJS).
- Main causes: Most cases are drug-induced (according to reports, >50% of SJS cases; the more severe toxic epidermal necrolysis [TEN] is drug-related in 80–95% of cases). Rare causes also include connective tissue disease, malignancy, graft-versus-host disease, infections (e.g., Mycoplasma pneumoniae and viruses), vaccination, and idiopathic causes. The causative drug is most likely to be a medication newly administered within 4 weeks before symptom onset.
- Pathophysiology (brief): An immune-mediated response to a specific drug or antigen causes massive keratinocyte death, destroying the epidermal–dermal junction and resulting in epidermal detachment. Mucous membranes (oral cavity, conjunctiva, vulva, etc.) are commonly involved, leading to ulceration and crust formation.
- Main symptoms: After fever and general malaise, erythematous macules → coalescence and blister formation → epidermal detachment (varying from several percent to >10% of the body surface area). Severe pain, tenderness, Nikolsky sign (the epidermis sloughs off when rubbed), ulcers of the oral cavity, lips, conjunctiva, and genital mucosa, and possible conjunctivitis, dry eye, and symblepharon. Systemic complications such as dyspnea (airway involvement), difficulty urinating, dehydration, and malnutrition may occur.
Treatment
- Initial principles
- Immediately discontinue suspected causative drugs (if possible, record the time of discontinuation and the medication list).
- Patients with severe disease should be hospitalized immediately (a burn unit or intensive care unit is recommended). Emergency transport is required for dyspnea, extensive epidermal detachment, multiple organ dysfunction, or signs of shock.
- Supportive care (key measures)
- Fluid and electrolyte correction, maintenance of body temperature and nutrition (high-protein, high-calorie), and pain control.
- Wound care: Sterile dressings similar to those used for burns, removal of necrotic tissue, and topical antimicrobial and protective dressings (caution is required when using topical agents that can be systemically absorbed).
- Infection prevention and treatment: Monitor for secondary skin infection and sepsis; use antibiotics when necessary (limited to confirmed infections).
- Ophthalmologic treatment
- Ophthalmologic care is needed from the early stage (to prevent symblepharon and chronic ocular complications). Use of tear substitutes, topical antibiotics, steroids, and lubricants, etc.
- Drug and immunologic treatment (considered in severe cases)
- Systemic corticosteroids: Their use is controversial, so administer cautiously for a short period after assessing benefits and risks (be cautious of the increased risk of infection).
- Intravenous immunoglobulin (IVIG), cyclosporine, plasma exchange, hemoperfusion (platelet sedimentation), and other treatments have been useful in some reports, but evidence is limited. Treatment choices should follow the judgment of the hospital and specialist.
- Other management
- If the respiratory tract is involved, secure the airway and provide mechanical ventilation. Manage urinary tract and genital mucosal involvement (e.g., urethral catheterization).
- After discharge: Long-term follow-up is needed for delayed recovery of the skin and mucous membranes, scarring and hyperpigmentation, chronic ocular problems, and other issues.
- Precautions
- Re-exposure (readministration) to the causative drug is absolutely prohibited because it can trigger a severe reaction again. The allergy and history of SJS must be clearly recorded in the complete medication history.
- Infection, multiorgan failure, and ocular damage (permanent vision loss) are major causes of death and morbidity.
- Prognostic factors
- Prognosis varies according to the extent of lesions, age, underlying diseases (such as immunosuppression and reduced kidney function), and the presence or absence of neutropenia. Overall mortality for SJS is low (reported at approximately 1%), whereas mortality for TEN is higher (5–50%), with substantial variation depending on severity. Assessment indicators such as SCORTEN are used to predict prognosis.
Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)
- Items to bring
- A list of all medications currently being taken (including prescription drugs, OTC medications, herbal medicines, and dietary supplements), with newly started medications from the past few weeks marked.
- Medical history (especially previous drug allergies or a history of SJS/TEN) and records of chronic diseases (such as kidney, liver, or immune system diseases).
- Photos showing the timing and progression of symptom onset (from the early skin lesions to the present).
- Copies of recent test results, if available (blood tests, culture results, chest imaging, etc.).
- A record of the timeline of symptoms (fever, rate of lesion spread, pain, difficulty swallowing, dyspnea, etc.).
- Checklist before an outpatient visit (symptoms/warning signs)
- Dyspnea, severe swelling of the tongue or throat mucosa, difficulty swallowing, or rapidly progressing extensive blisters/epidermal detachment requires a visit to the emergency department.
- Immediate ophthalmology referral is needed for severe conjunctival pain, decreased vision, or suspected eyelid adhesion.
- Key information to provide to the doctor during the outpatient visit
- All medications started within the past 6 weeks (especially anticonvulsants, sulfonamides, certain antibiotics, anti-inflammatory drugs, etc.), recent infections (respiratory symptoms, Mycoplasma infection, etc.), and vaccination history.
Examples of General Questions to Ask the Doctor
- "Which medication is suspected to be the cause of these symptoms, and should I stop any of the medications I am currently taking?"
- "What are the advantages and disadvantages of the treatment options (protective therapy, steroids, IVIG, cyclosporine, etc.), and what evidence supports the recommendations?"
- "What monitoring and preventive measures will you use to reduce the risk of infection?"
- "There is ocular involvement. What treatment and follow-up are needed to preserve my vision?"
- "After discharge, what should I watch for regarding recurrence and chronic complications involving the skin, eyes, and mucous membranes?"
Examples of Disease-Specific Questions
- "Could you confirm which of the medications I started recently are most likely to cause this disease? Are there any medications I should avoid permanently because of the risk of recurrence?"
- "My eye (conjunctiva/cornea) is involved. What is the visual prognosis in my current condition, and what long-term ophthalmologic follow-up examinations are needed?"