12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions

ABIM Internal Medicine Exam

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1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy

0.1 Exam Format, Question Types & the 2026 Blueprint 0.2 Eligibility, Registration, Fees & Exam-Day Logistics 0.3 Scoring, the Passing Standard & Score Reports 0.4 Building a Blueprint-Weighted Study Plan

2 Chapter 1: Cardiovascular Disease (14% of Exam)

1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection

3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)

2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia

4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)

3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV

5 Chapter 4: Infectious Disease (9% of Exam)

4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections

6 Chapter 5: Pulmonary Disease (9% of Exam)

5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule

7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)

6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease

8 Chapter 7: Hematology (6% of Exam)

7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation

9 Chapter 8: Medical Oncology (6% of Exam)

8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care

10 Chapter 9: Nephrology & Urology (6% of Exam)

9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria

11 Chapter 10: Neurology (4% of Exam)

10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders

12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)

11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health

13 Chapter 12: Dermatology (3% of Exam)

12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease

14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)

13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications

15 Chapter 14: Geriatric Syndromes (3% of Exam)

14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings

16 Chapter 15: Allergy & Immunology (2% of Exam)

15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology

16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design

18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)

17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity

19 Chapter 18: Perioperative Medicine & Medical Consultation

18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications

20 Chapter 19: Ophthalmology (1% of Exam)

19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease

21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)

20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders

12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions

Key Takeaways Explain This Topic AI

Dermatologic emergencies is a separately enumerated blueprint subsection under Dermatology.

Stevens-Johnson syndrome and toxic epidermal necrolysis are separated by the percentage of body surface with epidermal detachment.

Immediate withdrawal of the culprit drug and transfer to a burn or specialized unit are the interventions with the clearest survival benefit in toxic epidermal necrolysis.

Drug reaction with eosinophilia and systemic symptoms typically begins two to eight weeks after drug exposure with fever, facial edema, eosinophilia and organ involvement.

Mucosal involvement, skin tenderness, a positive Nikolsky sign, fever and lymphadenopathy are the features that separate a severe reaction from a simple morbilliform eruption.

Last updated: August 2026

• 1. Dermatologic Emergencies & Severe Cutaneous Adverse Reactions (SCAR)
• Stevens-Johnson Syndrome (SJS) & Toxic Epidermal Necrolysis (TEN)

Pathophysiology: A life-threatening, cell-mediated cytotoxic immune reaction culminating in massive, full-thickness keratinocyte apoptosis and extensive dermoepidermal sheet detachment. Mediated by cytotoxic CD8+ T lymphocytes and natural killer (NK) cells releasing granulysin , perforin, granzyme B, and Fas / Fas-Ligand (FasL) interactions.

High-Risk Culprit Medications (SATANE Mnemonic):

S — Sulfonamides: Trimethoprim-sulfamethoxazole (TMP-SMX), sulfadiazine, sulfasalazine.

A — Allopurinol: Especially in renal impairment or rapid dose titration.

T — Tetracyclines / Antiretrovirals: Nevirapine, efavirenz.

A — Anticonvulsants (Aromatic): Carbamazepine, Lamotrigine, Phenytoin, Phenobarbital.

N — NSAIDs: Oxicam derivatives (Piroxicam, Meloxicam).

E — Extras (Antibiotics): Beta-lactams, Cephalosporins, Fluoroquinolones.

Pharmacogenomic Risk Alleles:

HLA-B*15:02: Strongly associated with Carbamazepine-induced SJS/TEN in individuals of Asian ancestry (Han Chinese, Thai, Malaysian, Filipino). Mandatory FDA genetic screening prior to carbamazepine initiation.

HLA-B*58:01: Strongly associated with Allopurinol-induced SJS/TEN and DRESS in Han Chinese, Korean, Thai, and African-American ancestry.

HLA-B*57:01: Strongly associated with Abacavir hypersensitivity.

Clinical Presentation & Course:

Latency: 1 to 3 weeks (7-21 days) after drug initiation.

Prodrome: 1-3 days of fever, malaise, sore throat, cough, photophobia, and cutaneous tenderness.

Cutaneous Eruption: Rapidly spreading, dusky erythematous and purpuric macules with atypical targetoid lesions (2 concentric zones) that coalesce into flaccid blisters and extensive sheets of denuded skin. Positive Nikolsky sign (epidermal detachment induced by lateral frictional pressure) and Positive Asboe-Hansen sign .

Severe Mucosal Involvement (>90% of cases, >=2 distinct mucosal surfaces):

Eyes: Severe pseudomembranous conjunctivitis, corneal ulcerations, symblepharon (cicatricial adhesions of eyelids to globe), risk of permanent blindness.

Oral/Labial: Painful stomatitis, extensive sloughing, hemorrhagic vermilion crusting.

Genitourinary: Urethral/vaginal erosions, vulvar synechiae, urinary retention.

Respiratory: Tracheobronchial epithelial detachment causing acute respiratory distress syndrome (ARDS).

Classification by Body Surface Area (BSA) of Epidermal Detachment:

SJS: < 10% BSA epidermal detachment.

SJS / TEN Overlap: 10% to 30% BSA epidermal detachment.

TEN: > 30% BSA epidermal detachment (often >50-80%).

SCORTEN Prognostic Scoring System (Evaluated within first 24 hours):

• SCORTEN Parameter (1 point each) Clinical Threshold Mortality Rate by Total Score
• 1. Age >= 40 years 0 to 1 point: ~3.2% mortality
• 2. Associated Malignancy Yes (hematologic or solid tumor) 2 points: ~12.1% mortality
• 3. Tachycardia Heart Rate >= 120 beats/min 3 points: ~35.3% mortality
• 4. Initial Epidermal Detachment > 10% BSA at day 1 4 points: ~58.3% mortality
• 5. Serum Urea Nitrogen (BUN) > 28 mg/dL (>10 mmol/L) >= 5 points: ~90.0% mortality
• 6. Serum Glucose > 252 mg/dL (>14 mmol/L) —
• 7. Serum Bicarbonate (HCO3-) < 20 mEq/L (<20 mmol/L) —

Emergency Management Protocol:

Immediate Withdrawal of ALL Offending and Non-Essential Medications: Single most critical action affecting survival; each day of delay increases mortality.

Immediate Triage & Transfer to an Accredited Burn Center or Intensive Care Unit (ICU): Specialized nursing, thermoregulation (room temp 30-32°C), and infection control.

Supportive Resuscitation: IV fluid resuscitation with balanced crystalloids titrated to urine output (target 0.5-1.0 mL/kg/h; requires ~25-30% less volume than equivalent thermal burns to avoid pulmonary edema). Enteral nutrition via soft nasogastric tube.

Wound Care: Sterile handling, bland non-adherent dressings (silicone dressings, petrolatum gauze); DO NOT surgically debride non-detached necrotic epidermis (detached skin serves as a biological dressing).

Infection Control: Daily surveillance cultures; NO prophylactic systemic antibiotics (increases selective pressure for resistant Pseudomonas and fungal sepsis); treat only documented infections.

Urgent Ophthalmology Consultation: Aggressive preservative-free lubrication, topical antibiotics, lysis of symblepharon adhesions, and early Amniotic Membrane Transplantation (AMT) within the first 5-7 days to prevent cicatrization and permanent blindness.

Immunomodulatory Therapies: Cyclosporine A (3-5 mg/kg/day IV/PO for 10-14 days; halts apoptosis and improves survival in meta-analyses), Etanercept (anti-TNF; 50 mg SC), or IVIG (2-3 g/kg). High-dose systemic steroids remain controversial due to sepsis risks.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS / DIHS)

Pathophysiology: A severe, life-threatening delayed-type hypersensitivity reaction (Type IVb/IVc) driven by drug-specific T-cell activation in synergy with the reactivation of latent human herpesviruses, predominantly Human Herpesvirus 6 (HHV-6) , HHV-7, Epstein-Barr Virus (EBV), and Cytomegalovirus (CMV).

High-Risk Culprit Drugs: Allopurinol , Aromatic Anticonvulsants ( Carbamazepine, Phenytoin, Lamotrigine ), Sulfonamides , Vancomycin , Minocycline , and Dapsone .

Characteristic Timeline: Prolonged, delayed latency of 2 to 8 WEEKS (average 3-4 weeks) between drug initiation and symptom onset (distinguishing DRESS from simple morbilliform drug exanthems [1-2 weeks] or SJS/TEN).

Clinical Triad & Organ Manifestations:

High Prolonged Fever (>=38.5°C): Present in >90% of patients.

Extensive Cutaneous Eruption: Confluent morbilliform, indurated maculopapular eruption covering >50% BSA, with marked facial edema and periorbital swelling (>70-80% of cases; key diagnostic hallmark) and tender generalized lymphadenopathy.

Multisystem Internal Organ Failure:

Liver (70-90%): Severe acute hepatitis with marked transaminitis (ALT/AST >5x ULN), cholestasis, or fulminant hepatic failure.

Kidney (10-30%): Acute interstitial nephritis (AIN) with elevated creatinine, proteinuria, and eosinophiluria (classically associated with Allopurinol).

Lungs (10-15%): Interstitial pneumonitis, dry cough, hypoxemia.

Heart (2-5%): Acute Eosinophilic or Delayed Hypersensitivity Myocarditis (can emerge weeks after rash resolution; presents with cardiogenic shock, arrhythmias, or sudden death; requires troponin and echocardiogram screening).

Laboratory Hallmarks:

Marked Peripheral Eosinophilia (>= 700 to 1,500/mcL or > 10% total WBC count; present in >90%).

Atypical Lymphocytosis (mononucleosis-like reactive Downey lymphocytes).

Quantitative PCR detection of circulating HHV-6 DNA.

Management & Monitoring:

Immediate cessation of the offending medication.

Systemic Corticosteroids: Oral Prednisone 0.5 to 1.0 mg/kg/day (or IV Methylprednisolone for severe organ dysfunction).

CRITICAL MANAGEMENT RULE: Corticosteroids must be tapered very slowly over 2 to 3 MONTHS (8 to 12 weeks) . Rapid steroid tapering triggers severe, fatal disease rebound and recurrent hepatitis.

Long-Term Monitoring: Screen for delayed autoimmune sequelae (Autoimmune Thyroiditis [Hashimoto's or Graves'], Type 1 Diabetes Mellitus, Vitiligo, Systemic Lupus) occurring 6 to 12 months after resolution.

Acute Generalized Exanthematous Pustulosis (AGEP)

Pathophysiology: T-cell mediated hypersensitivity (Type IVd) where drug-specific CD4+/CD8+ T cells produce massive quantities of Interleukin-8 (CXCL8) , orchestrating rapid, massive neutrophilic recruitment into the subcorneal epidermis.

Culprit Medications: Beta-lactam antibiotics (Aminopenicillins, Cephalosporins) , Macrolides, Quinolones, Hydroxychloroquine, and Diltiazem.

Clinical Presentation:

Ultra-rapid onset: Erupts within 24 to 48 HOURS (1-2 days) of drug ingestion.

High fever (>=38°C) and sudden emergence of dozens to hundreds of tiny (1-2 mm), non-follicular, sterile pinpoint pustules arising on a background of diffuse, edematous erythema. Typically begins in flexural/intertriginous skin folds (axillae, groin, neck) and rapidly disseminates.

Labs: Marked leukocytosis with profound neutrophilia (ANC >7,000 to 10,000/mcL); eosinophilia in <30%.

Clinical Course & Management: Self-limiting benign course . Discontinue the offending antibiotic. Pustules spontaneously desquamate with a characteristic "collarette" pinpoint peeling within 7 to 14 days . Managed supportively with bland emollients and cool compresses; systemic corticosteroids are rarely necessary.