5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease

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

5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease

Key Takeaways Explain This Topic AI

Organic inhalations, inorganic inhalations, occupational asthma, high-altitude illness and carbon monoxide poisoning are enumerated under occupational and environmental lung disease.

Lofgren syndrome of erythema nodosum, bilateral hilar adenopathy, fever and arthritis is a favorable sarcoidosis presentation often managed without corticosteroids.

Hypersensitivity pneumonitis requires identification and removal of the inciting antigen, which is the single most important intervention.

Silicosis markedly increases tuberculosis risk, so latent tuberculosis screening is mandatory in exposed workers.

Eggshell calcification of hilar nodes suggests silicosis, and pleural plaques indicate asbestos exposure rather than asbestosis itself.

Last updated: August 2026

1. Sarcoidosis

Sarcoidosis is a multisystem inflammatory disorder characterized pathologically by the accumulation of noncaseating epithelioid granulomas in affected organs, most commonly the lungs and intrathoracic lymph nodes (>90% of cases).

Epidemiology & Pathophysiology

Demographics: Peaks in young-to-middle-aged adults (20–45 years); 3- to 4-fold higher incidence and greater clinical severity in African Americans (particularly women) and individuals of Scandinavian descent.

Immunopathology: CD4+ T-helper 1 (Th1) and Th17 cell hyperactivation driven by persistent antigen presentation, leading to interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and TNF-alpha secretion. Bronchoalveolar lavage (BAL) characteristically reveals a marked lymphocytic alveolitis with an elevated CD4+/CD8+ ratio > 3.5:1 .

Calcium Metabolism Abnormalities: Activated alveolar macrophages within granulomas express 1-alpha-hydroxylase in an unregulated fashion, converting 25-hydroxyvitamin D into active 1,25-dihydroxyvitamin D (Calcitriol) independent of PTH. This results in hypercalciuria (common, ~30%) and hypercalcemia (~10%) with suppressed PTH and hypercalciuric nephrocalcinosis/nephrolithiasis.

Scadding Radiographic Staging (Chest X-Ray)

• Stage Radiographic Findings Typical Spontaneous Resolution Rate
• Stage 0 Normal chest radiograph (5–10% of presentations) N/A

Stage I Bilateral Hilar Lymphadenopathy (BHL) alone (+/- right paratracheal node enlargement) 60% – 80% spontaneous remission

Stage II Bilateral Hilar Lymphadenopathy + Parenchymal Infiltrates (reticulonodular upper/mid zone) 50% – 60% spontaneous remission

Stage III Parenchymal Infiltrates alone (diffuse fibrosis/opacities without hilar adenopathy) 20% – 30% spontaneous remission

Stage IV End-Stage Pulmonary Fibrosis (honeycombing, architectural distortion, upward hilar retraction) 0% (Permanent, irreversible damage)

Classical Clinical Syndromes & Extrapulmonary Screening

Löfgren Syndrome: Classic acute benign presentation characterized by the clinical triad of:

• Bilateral hilar lymphadenopathy (BHL)
• Erythema nodosum (tender, erythematous subcutaneous pretibial nodules)
• Migratory polyarthritis or periarthritis (especially affecting bilateral ankles)

Prognosis & Management: Excellent prognosis with >85% spontaneous remission within 1–2 years. Treated with NSAIDs alone for symptom relief. Systemic corticosteroids and invasive tissue biopsy are NOT required when the classic triad is present.

Heerfordt Syndrome (Uveoparotid Fever): Rare manifestation presenting with parotid gland enlargement, anterior uveitis, low-grade fever, and cranial nerve VII (facial) palsy.

Cardiac Sarcoidosis: Present in up to 25% of sarcoidosis autopsies. Manifests as complete atrioventricular (AV) heart block, ventricular arrhythmias (VT/VF), sudden cardiac death, or dilated cardiomyopathy. All patients with sarcoidosis require a baseline 12-lead ECG . If abnormal or palpitations/syncope occur, evaluate immediately with Cardiac MRI (late gadolinium enhancement) or 18F-FDG PET-CT .

Ocular Sarcoidosis: Anterior/posterior uveitis, retinal vasculitis, or optic neuritis. Requires a mandatory baseline slit-lamp ophthalmologic examination in all patients.

Neurosarcoidosis: Cranial neuropathies (CN VII palsy most common), aseptic meningitis, hypothalamic-pituitary dysfunction (diabetes insipidus), or seizures.

Indications for Systemic Corticosteroids

Asymptomatic Stage I or stable mild Stage II pulmonary sarcoidosis does not require treatment (observation with serial PFTs every 3–6 months is standard).

Mandatory Indications for Treatment:

• Progressive or symptomatic pulmonary disease (worsening dyspnea, declining FVC/DLCO)
• Cardiac sarcoidosis (AV block, ventricular arrhythmias, cardiomyopathy)
• Neurosarcoidosis
• Ocular sarcoidosis refractory to topical ophthalmic steroids
• Persistent hypercalcemia or nephrocalcinosis
• Disfiguring lupus pernio or symptomatic hepatosplenomegaly

Therapeutic Regimen: Oral Prednisone 20–40 mg daily for 1–3 months, tapered over 6–12 months. Second-line steroid-sparing agents: Methotrexate (first-line add-on), Azathioprine, or Leflunomide. Refractory cases: Infliximab (anti-TNF-alpha).

2. Hypersensitivity Pneumonitis (Extrinsic Allergic Alveolitis)

Hypersensitivity Pneumonitis (HP) is an immune-mediated interstitial and bronchiolar lung disease triggered by repeated inhalation of environmental organic antigens (fungal spores, avian proteins, bacterial products) or low-molecular-weight chemicals in sensitized hosts.

Major Etiologic Antigens

Farmer's Lung: Inhalation of thermophilic actinomycetes ( Saccharopolyspora rectivirgula , Thermoactinomyces vulgaris ) from moldy hay or compost.

Bird Fancier's / Pigeon Breeder's Lung: Inhalation of avian serum proteins (droppings, bloom, feathers from pigeons, parakeets, chickens, down duvets/pillows).

Hot Tub / Humidifier Lung: Inhalation of non-tuberculous mycobacteria ( Mycobacterium avium complex) or molds ( Aureobasidium , Cephalosporium ) from contaminated aerosols.

Chemical Worker's Lung: Inhalation of diisocyanates (polyurethane paints, foams) or trimellitic anhydride.

Diagnostic Hallmarks

Clinical Phenotypes:

Non-Fibrotic (Acute/Subacute) HP: Flu-like illness with fever, chills, non-productive cough, and dyspnea developing 4–8 hours after antigen re-exposure, resolving over 24–48 hours away from the exposure.

Fibrotic (Chronic) HP: Insidious onset of progressive exertional dyspnea, fatigue, weight loss, and crackles due to continuous low-dose exposure.

Bronchoalveolar Lavage (BAL): Marked lymphocytic alveolitis (>20–40% lymphocytes) , often with a normal or low CD4+/CD8+ ratio (<1.0).

HRCT Chest: Centrilobular ground-glass nodules, mosaic perfusion, and expiratory air-trapping. The pathognomonic "headcheese sign" (three-density sign) consists of juxtaposed areas of ground-glass opacity, normal lung attenuation, and lucent hypoperfused air-trapping on inspiratory and expiratory images.

Management: Complete and strict avoidance of the offending environmental antigen is the cornerstone of treatment and the only intervention that halts disease progression. Oral corticosteroids (Prednisone 0.5–1 mg/kg/day tapered over 1–3 months) accelerate recovery in acute/subacute disease with physiological impairment.

3. Pneumoconioses: Occupational Mineral Dust Diseases

Pneumoconioses are non-neoplastic lung diseases caused by the inhalation, deposition, and tissue reaction to inorganic mineral dusts in industrial workplaces.

Summary of Major Pneumoconioses

Condition Industrial Exposure Key Radiographic / Pathologic Findings Major Complications & Board Pearls

Silicosis Sandblasting, rock quarrying, tunneling, granite cutting, foundry work, ceramics, glass manufacturing. - Chest X-Ray: Multiple small, discrete rounded nodular opacities (1–10 mm) predominantly in the upper lung lobes .; - Classic "Eggshell Calcification" of hilar and mediastinal lymph nodes (thin calcified rim).; - Histology: Concentric, whorled hyalinized collagenous silicotic nodules with weakly birefringent silica crystals under polarized light. - Silicotuberculosis: Silica impairs alveolar macrophage phagolysosomal killing of Mycobacterium tuberculosis .; - Mandatory annual TB screening with TST (PPD) or IGRA.; - A TST induration >= 5 mm is considered POSITIVE in silicosis.; - Increased risk of lung cancer and systemic sclerosis (Erasmus syndrome).

Asbestosis & Asbestos Pleural Disease Shipbuilding, naval shipyards, pipefitting, construction demolition, boiler making, insulation, automotive brake repair (latency 15–40+ years). - Benign Pleural Plaques: Well-circumscribed fibrocalcific plaques on the parietal pleura and dome of the diaphragm (sparing costophrenic angles). Most common manifestation; indicates exposure only (not premalignant).; - Asbestosis (Parenchymal Fibrosis): Bibasilar reticular interstitial fibrosis, honeycombing, and thickened pleura.; - Histology: Asbestos (ferruginous) bodies (golden-brown beaded dumbbell-shaped fibers coated with hemosiderin-protein). - Bronchogenic Carcinoma: Most common malignancy in asbestos workers; risk is multiplicatively synergistic with cigarette smoking (up to 50–90x risk) .; - Malignant Mesothelioma: Aggressive tumor of the parietal pleura presenting with pleuritic pain, dyspnea, and hemorrhagic pleural effusion with nodular pleural rind. NOT associated with cigarette smoking ; associated almost exclusively with asbestos exposure.

Coal Workers' Pneumoconiosis (CWP) Underground coal mining (anthracite coal miners). - Simple CWP: Small rounded opacities (coal macules / nodules) in upper lung zones .; - Complicated CWP: Progressive Massive Fibrosis (PMF) with large confluent fibrotic masses (>1 cm) causing cavitation and severe restrictive/obstructive impairment. - Caplan Syndrome: Combination of pneumoconiosis (CWP or silicosis) with Rheumatoid Arthritis , presenting as multiple well-defined peripheral pulmonary rheumatoid nodules (1–5 cm) that may cavitate.