1) Disease Description (Causes and Symptoms)
- Summary of definition: A serious drug-related immune-mediated mucocutaneous disease that causes acute, generalized detachment of mucous membranes and skin, characterized by epidermal detachment and multiple mucosal lesions. It forms a spectrum with toxic epidermal necrolysis (TEN).
- Main causes
- Most cases are drug-induced (a considerable proportion of all patients; figures vary by report; drugs are the most common cause in SJS/TEN).
- Rarely occurs due to infections (such as Mycoplasma pneumoniae), vaccinations, connective tissue diseases, graft-versus-host disease, and some malignancies.
- Approximately 5% have no identified cause (idiopathic).
- The causative drug generally triggers the condition within several days to 4 weeks after a new drug is started.
- Brief explanation of pathophysiology
- An immune response caused by a drug or pathogen leads to massive necrosis of keratinocytes at the epidermal junction → epidermal detachment and mucosal ulceration.
- Main symptoms
- Erythematous macules occurring after fever and generalized malaise → coalescing to form blisters → epidermal detachment (which may progress extensively over part of the body surface).
- Mucosal involvement in nearly all patients, including oral and lip lesions (as well as the eyes, genitals, anus, and other areas).
- Skin tenderness and possible positive Nikolsky sign. Hemorrhagic crusts and ulcers, hair loss, and nail changes may also occur.
- Eye symptoms: conjunctivitis, symblepharon (which may affect vision if severe), dry eyes, and others.
- Systemic organ involvement may occur, including difficulty breathing, difficulty urinating, and nutritional impairment due to gastrointestinal tract damage.
- Prognostic indicators
- Extensive lesions, older age, neutropenia, impaired kidney function, and multiple-medication use are factors associated with a poor prognosis.
- Reported mortality: relatively low for SJS (approximately 1%), and high for TEN (varying from several percent to several tens of percent).
2) Treatment (Standard Treatment · Medications · Procedures · Lifestyle Management · Precautions)
- Immediate treatment
- Immediately discontinue the suspected causative drug (the most important first step).
- Immediate hospitalization depending on severity (consultation with an intensive care unit or a burn specialist (burn unit) is recommended).
- Supportive care (core treatment)
- Fluid and electrolyte management, pain control, nutrition (high-calorie and high-protein), and conservative wound care (sterile dressings).
- Prevention and early detection of secondary bacterial infections (if a wound is infected, antibiotic use is based on culture results and clinical findings).
- Mechanical ventilation and airway protection in cases of respiratory impairment.
- Skin and mucosal treatment
- Burn-like treatment: hydrocolloids, gauze dressings, and others; skin grafting may be considered for extensive detachment (in severe cases).
- Consider the possibility of systemic absorption when using topical agents.
- Ophthalmologic management
- Early consultation with an ophthalmologist is essential. Lubricating eye drops, topical antibiotics, and specialized treatment when necessary (such as surgery to prevent symblepharon).
- Immunomodulatory treatment (evidence and limitations)
- Steroids (may be administered for a short period early in the course, but should be used cautiously because their effectiveness and infection risk are controversial).
- Intravenous immunoglobulin (IVIG), cyclosporine, plasma exchange, and others are used in some cases, but the evidence and effectiveness vary among studies. Treatment should be performed at the discretion of the treating team.
- Other
- Management of complications such as infection, kidney failure, and respiratory failure.
- Lifestyle management and precautions after discharge
- The causative drug and related structurally similar drugs (drugs in the same class) are contraindicated for life (determine alternative medications after consulting a doctor).
- Long-term follow-up is necessary for chronic complications of the skin and eyes (such as skin pigmentation abnormalities, dry eyes, and symblepharon).
- To reduce the risk of recurrence, carrying a medical allergy card or a list of drug allergies is recommended.
3) 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, over-the-counter medications, herbal medicines, and health functional foods), with recently started medications marked
- The time symptoms began and their progression (photos or a symptom diary are recommended)
- A history of previous allergies or skin diseases and whether similar reactions have occurred before
- Information about recent vaccinations or infections (e.g., pneumonia)
- Recent test results, if available (such as blood tests, kidney function tests, and skin biopsy results)
- Materials to show the doctor during the outpatient visit
- Photos of the skin lesions (including photos from the early stage of onset), a list of medications taken, and prescriptions or medication packaging from immediately before onset
- Emergency signs (immediate emergency room visit required)
- Sudden severe difficulty breathing, difficulty swallowing, widespread blisters or severe epidermal detachment, high fever, low blood pressure, or altered consciousness, severe eye pain or decreased vision, and rapidly decreasing urine output
4) Examples of General Questions to Ask the Doctor
- "How can we determine which medication is suspected to be the cause of this reaction?"
- "How do you assess the severity of my current symptoms and my prognosis?"
- "If I stop taking my current medication, what alternative medications are available?"
- "What are the criteria for hospitalization and intensive treatment?"
- "How will long-term complications, especially eye-related complications, be prevented and monitored?"
5) Examples of Disease-Specific Questions (1–2)
- "Among the medications I recently started taking, how do you determine epidemiologically and clinically which one was most likely to have caused this reaction?"
- "If there is eye involvement, which ophthalmologic treatments (such as eye drops or surgical procedures) should be prioritized early, and what is the plan for protecting vision in the long term?"