Study guide
12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses
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
12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses
Key Takeaways Explain This Topic AI
Atopic, contact, photo-, stasis, hand, nummular, exfoliative and seborrheic dermatitis and drug eruptions are enumerated under dermatitis.
Psoriasis, pityriasis rosea and lichen planus are the three enumerated papulosquamous dermatoses.
Systemic corticosteroids are avoided in psoriasis because withdrawal can precipitate pustular or erythrodermic flares.
Topical steroid potency must be matched to site, using low potency on the face, intertriginous areas and genitals to avoid atrophy.
Stasis dermatitis is frequently misdiagnosed as bilateral cellulitis, which is rare, leading to unnecessary antibiotics.
Last updated: August 2026
Cutaneous disorders represent a significant proportion of internal medicine ambulatory and inpatient consultations. A rigorous understanding of epidermal barrier biology, autoimmune effector pathways, clinical differentiation between infectious and inflammatory mimickers, and evidence-based topical and biologic pharmacotherapies is essential for the ABIM certification exam.
- 1. Inflammatory Dermatoses
- Atopic Dermatitis (Eczema)
Pathophysiology: A chronic, pruritic, relapsing inflammatory skin disease driven by a complex interplay of epidermal barrier disruption , immune dysregulation (T-helper 2 [Th2] cell-skewed immune response with excess interleukin-4 [IL-4] and interleukin-13 [IL-13]), and environmental triggers. Loss-of-function mutations in the filaggrin ( FLG ) gene impair stratum corneum integrity, leading to increased transepidermal water loss (TEWL) and enhanced penetration of cutaneous allergens and microbes.
Clinical Presentation:
Morphology: Intensely pruritic, erythematous papules and patches that coalesce into scaly, excoriated plaques with lichenification (thickened skin with exaggerated markings from chronic rubbing).
Distribution: Strongly age-dependent. In adolescents and adults, lesions classically involve flexural surfaces (antecubital and popliteal fossae, anterior neck, dorsal hands and wrists). In infants, lesions predominantly affect the face, scalp, and extensor surfaces of extremities, sparing the diaper area.
Atopic Triad ("Allergic March"): Personal or family history of atopic dermatitis, allergic rhinitis, and asthma.
Complications: Increased susceptibility to cutaneous viral infections, most notably Eczema Herpeticum (Kaposi varicelliform eruption) caused by Herpes Simplex Virus (HSV-1/2) superinfection. Eczema herpeticum presents as sudden eruption of monomorphic, punched-out, umbilicated vesicles and erosions over pre-existing eczematous skin accompanied by high fever and lymphadenopathy; it is a dermatologic emergency requiring prompt systemic oral or IV Acyclovir .
Stepwise Management Strategy:
Foundational Skin Care (All Patients): Lukewarm, brief baths (5-10 minutes); mild fragrance-free non-soap synthetic cleansers; immediate application (within 3 minutes) of thick ceramide-containing emollients/ointments to trap cutaneous moisture; avoidance of harsh detergents and known contact allergens.
First-Line Acute Flare Therapy: Topical Corticosteroids (TCS) :
Face, eyelids, neck, and intertriginous areas: Low-potency TCS (e.g., Hydrocortisone 1% to 2.5%, Desonide 0.05% cream) to prevent cutaneous atrophy, telangiectasias, striae, and glaucoma/cataracts.
Trunk and extremities: Medium-to-high potency TCS (e.g., Triamcinolone acetonide 0.1%, Betamethasone dipropionate 0.05% cream/ointment) applied once to twice daily during active flares, then tapered.
Steroid-Sparing Topicals (Maintenance & Sensitive Areas):
Topical Calcineurin Inhibitors (TCIs): Tacrolimus 0.03%-0.1% ointment or Pimecrolimus 1% cream . Inhibit T-cell activation by blocking calcineurin phosphatase. Excellent for facial, periorbital, and genital eczema without risk of skin atrophy.
Topical PDE-4 Inhibitor: Crisaborole 2% ointment (reduces intracellular cAMP degradation and downstream cytokine release).
Topical JAK Inhibitor: Ruxolitinib 1.5% cream (blocks JAK1/JAK2 signaling).
Moderate-to-Severe Refractory Disease:
Phototherapy: Narrowband Ultraviolet B (NB-UVB).
Targeted Biologics: Dupilumab (human monoclonal antibody directed against the IL-4 receptor alpha [IL-4Rα] subunit , dual-inhibiting both IL-4 and IL-13 signaling; administered as 600 mg SC loading dose followed by 300 mg SC every 2 weeks). Highly effective with favorable safety; key adverse effect is allergic conjunctivitis and blepharitis. Tralokinumab (anti-IL-13 antibody).
Oral JAK Inhibitors: Upadacitinib or Abrocitinib (rapid onset of pruritus relief for severe refractory disease; requires monitoring for cytopenias, lipid elevations, and thrombosis risks).
Psoriasis Vulgaris
Pathophysiology: Autoimmune, polygenic inflammatory disorder mediated by the IL-23 / Th17 / IL-17 cytokine axis . Antigen-presenting dendritic cells produce IL-23, which stimulates Th17 lymphocytes to secrete IL-17A, IL-17F, and IL-22. These cytokines drive marked keratinocyte hyperproliferation (epidermal transit time shortened from 28 days to 3-5 days), parakeratosis (retention of nuclei in stratum corneum), and dermal microvascular elongation.
Clinical Subtypes & Features:
Chronic Plaque Psoriasis (Psoriasis vulgaris, ~85-90%): Well-demarcated, symmetrically distributed, erythematous plaques covered with coarse, silvery-white micaceous scales located over extensor surfaces (elbows, knees, scalp, lumbosacral region, umbilicus, gluteal cleft).
Classic Physical Exam Signs:
Auspitz Sign: Pinpoint bleeding when silvery scales are scraped off or removed, resulting from exposed and ruptured dilated dermal papillary capillaries beneath the thinned suprapapillary epidermal plates.
Koebner Phenomenon (Isomorphic Response): Development of new psoriatic plaques at sites of mechanical trauma, excoriation, or surgical incisions (shared with lichen planus and vitiligo).
Psoriatic Nail Disease (>50% of patients): Pitting (punctate depressions in nail plate), "oil-drop" or "salmon patch" subungual discoloration, subungual hyperkeratosis, and onycholysis (distal detachment of nail plate). Nail involvement strongly correlates with concomitant Psoriatic Arthritis (PsA) .
Guttate Psoriasis: Acute, eruptive onset of hundreds of small (2-10 mm) "drop-like" erythematous scaly papules and plaques over the trunk and proximal extremities, classically arising 1 to 3 weeks following Streptococcus pyogenes (Group A Strep) pharyngitis in children and young adults. Often self-limiting or responsive to phototherapy and topical corticosteroids.
Inverse (Intertriginous) Psoriasis: Smooth, glistening, deep-red plaques without scales located within skin folds (axillae, inframammary, groin, perineal, and intergluteal clefts). Easily mistaken for Candida intertrigo or tinea cruris (distinguished by sharp borders and absence of satellite pustules).
Pustular & Erythrodermic Psoriasis: Severe, life-threatening variants. Generalized pustular psoriasis (GPP / von Zumbusch) features widespread sterile pustules on fiery red skin with high fever and leukocytosis.
Stepwise Management Strategy:
Localized Mild-to-Moderate Disease (<5-10% Body Surface Area [BSA]):
First-Line: High-potency Topical Corticosteroid (e.g., Clobetasol propionate 0.05%, Betamethasone dipropionate 0.05%) PLUS a Topical Vitamin D3 Analog (Calcipotriene 0.005% or Calcitriol 3 mcg/g) . Combination therapy provides synergistic efficacy while mitigating corticosteroid-induced epidermal atrophy.
Topical Retinoids (Tazarotene 0.05-0.1%): Normalizes keratinocyte differentiation; best used in combination with TCS to reduce local irritation.
Topical Calcineurin Inhibitors (Tacrolimus/Pimecrolimus): Preferred for facial and inverse intertriginous psoriasis.
Moderate-to-Severe Disease (>10% BSA, Psoriatic Arthritis, or High-Impact Areas [hands, feet, scalp, genitals]):
Phototherapy: Narrowband UVB (NB-UVB) 3 times weekly.
Oral Systemic Agents:
Methotrexate (7.5-25 mg PO/SC once weekly + daily Folic acid 1 mg): Inactivates dihydrofolate reductase; effective for cutaneous psoriasis and psoriatic arthritis. Monitor CBC (myelosuppression), LFTs (hepatotoxicity/cirrhosis), and pulmonary symptoms.
Apremilast (30 mg PO BID): Oral phosphodiesterase-4 (PDE-4) inhibitor increasing intracellular cAMP. No routine laboratory monitoring required; common adverse effects are diarrhea, nausea, headache, weight loss, and depression.
Acitretin: Oral retinoid; highly teratogenic (pregnancy contraindicated during and for 3 years post-discontinuation; avoid alcohol which converts acitretin to etretinate).
Biologic Therapies (Standard First-Line for Severe Disease & PsA):
Anti-TNF-alpha agents: Adalimumab, Infliximab, Etanercept, Certolizumab pegol (screen with QuantiFERON-TB and HBV panel prior to initiation).
Anti-IL-17A inhibitors: Secukinumab , Ixekizumab , Bimekizumab (dual IL-17A/F inhibitor). Rapid, profound plaque clearance; risk of mucocutaneous candidiasis and exacerbation of inflammatory bowel disease (contraindicated in active Crohn's disease).
Anti-IL-23 (p19 subunit) inhibitors: Guselkumab , Risankizumab , Tildrakizumab . High durability, superior PASI-90/100 clearance rates, administered every 8-12 weeks.
Anti-IL-12/23 (p40 subunit) inhibitor: Ustekinumab .
ABIM Board Pearl — Systemic Corticosteroids Contraindication: NEVER treat psoriasis flares with systemic oral corticosteroids (e.g., oral Prednisone or Medrol dose pack). Although oral steroids produce rapid initial improvement, tapering or discontinuing them triggers severe, life-threatening rebound generalized pustular psoriasis (GPP) or erythrodermic psoriasis with high morbidity and mortality.