Study guide
5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus
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
5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus
Key Takeaways Explain This Topic AI
Asthma is enumerated under Allergy and Immunology as well as Pulmonary Disease, with exercise-induced, occupational and pregnancy-related forms named separately.
Diagnosis requires demonstrating variable expiratory airflow limitation, typically bronchodilator reversibility or a positive bronchoprovocation test.
Short-acting beta-agonist monotherapy is no longer recommended because it treats symptoms without addressing airway inflammation.
A normal or rising arterial carbon dioxide tension during a severe exacerbation signals impending respiratory failure rather than improvement.
Asthma mimics including vocal cord dysfunction are explicitly listed in the blueprint and should be considered when therapy fails.
Last updated: August 2026
1. Asthma: Diagnosis & GINA 2024 Guidelines
Asthma is a chronic inflammatory disorder of the conducting airways characterized by bronchial hyperresponsiveness and variable, reversible airflow limitation.
Objective Diagnostic Criteria
Reversible Airflow Limitation on Spirometry: A post-bronchodilator increase in FEV1 of > 12% AND > 200 mL compared with baseline pre-bronchodilator FEV1 (measured 10–15 minutes after 200–400 mcg albuterol).
Bronchoprovocation Testing (Methacholine Challenge): Used when asthma is clinically suspected but baseline spirometry is normal. A PC20 (provocative concentration causing a >=20% fall in FEV1) <= 8 mg/mL confirms airway hyperresponsiveness (high negative predictive value; if negative, asthma is virtually excluded).
Fractional Exhaled Nitric Oxide (FeNO): FeNO > 50 ppb in adults correlates with active Type 2 eosinophilic airway inflammation and predicts positive responsiveness to inhaled corticosteroids.
GINA 2024 Management Tracks
GINA divides asthma management into two primary tracks. Track 1 is the preferred strategy across all severity steps because it substantially reduces the risk of severe exacerbations and asthma-related mortality compared with traditional SABA-only relief.
Track 1: Preferred Strategy (Anti-Inflammatory Reliever / SMART):
The reliever is low-dose ICS-formoterol taken as needed across all steps.
Mechanism: Formoterol is a long-acting beta-2 agonist (LABA) with an onset of action as rapid as albuterol (1–3 minutes) combined with a 12-hour duration of action. Co-administering low-dose budesonide (or beclomethasone) whenever the patient experiences symptoms delivers an immediate burst of anti-inflammatory therapy at the earliest onset of an exacerbation.
Step 1 & 2: Low-dose ICS-formoterol as needed only for symptom relief (no daily scheduled controller).
Step 3: Low-dose maintenance ICS-formoterol (1 inhalation daily or BID) + low-dose ICS-formoterol as needed for relief (Single Maintenance and Reliever Therapy — SMART / MART ).
Step 4: Medium-dose maintenance ICS-formoterol (2 inhalations BID) + low-dose ICS-formoterol as needed for relief.
Step 5: High-dose maintenance ICS-formoterol + add-on LAMA (Tiotropium Respimat 2.5 mcg daily) + phenotypic evaluation for biologic therapy .
Track 2: Alternative Strategy: Regular daily ICS (or ICS-LABA) maintenance with as-needed SABA (Albuterol) reliever. (Requires verified adherence to daily controller before prescribing SABA).
Add-On Biologic Therapies for Severe Uncontrolled Asthma (Step 5)
Biologic Agent Target / Mechanism Approved Phenotype & Biomarker Indications
Omalizumab Anti-IgE monoclonal antibody (binds free circulating IgE, preventing binding to Fc-epsilon-RI receptors on mast cells/basophils) Severe Allergic Asthma: Positive skin test or in vitro reactivity to a perennial aeroallergen + baseline serum total IgE 30–700 IU/mL (dosed by weight and baseline IgE).
Mepolizumab (SC) / Reslizumab (IV) Anti-Interleukin-5 (IL-5) monoclonal antibody (neutralizes circulating IL-5, blocking eosinophil maturation and survival) Severe Eosinophilic Asthma: Baseline blood eosinophils >= 150–300 cells/mcL with frequent exacerbations.
Benralizumab (SC) Anti-IL-5 Receptor alpha (IL-5R-alpha) subunit (binds IL-5R on eosinophils and basophils, inducing antibody-dependent cellular cytotoxicity [ADCC]) Severe Eosinophilic Asthma: Baseline blood eosinophils >= 300 cells/mcL ; produces rapid, near-complete depletion of circulating and tissue eosinophils.
Dupilumab (SC) Anti-IL-4 Receptor alpha (IL-4R-alpha) subunit (inhibits dual signaling of both IL-4 and IL-13 ) Severe Eosinophilic Asthma (eosinophils >= 150 cells/mcL or FeNO >= 25 ppb) OR Oral Corticosteroid-Dependent Asthma . Also indicated for comorbid atopic dermatitis and chronic rhinosinusitis with nasal polyps (CRSwNP).
Tezepelumab (SC) Anti-Thymic Stromal Lymphopoietin (TSLP) monoclonal antibody (blocks epithelial alarmin upstream of both T2 and non-T2 inflammation) Severe Uncontrolled Asthma without phenotypic restriction (effective in both eosinophilic/allergic and non-eosinophilic / T2-low asthma).
- 2. Severe Acute Asthma Exacerbation (Status Asthmaticus)
- Acute Resuscitation Protocol
High-Dose Inhaled Bronchodilators: Albuterol 2.5–5 mg plus Ipratropium bromide 0.5 mg via nebulizer every 20 minutes for 3 doses, or continuous nebulized albuterol (10–15 mg/hour).
Systemic Corticosteroids: Early administration is critical. Oral Prednisone 40–60 mg or IV Methylprednisolone 60–125 mg. Corticosteroids take 4–6 hours to exert clinical genomic anti-inflammatory effects.
Intravenous Magnesium Sulfate: 2 g IV infusion over 20 minutes . Indicated for severe exacerbations with persistent hypoxemia, FEV1 < 40% predicted, or lack of response after 1 hour of intensive bronchodilator therapy. Acts via calcium channel antagonism on bronchial smooth muscle causing smooth muscle relaxation.
Controlled Oxygen Therapy: Target SaO2 93–95% in adults (94–98% in pregnant women). Hyperoxia should be avoided to prevent V/Q mismatch worsening and hypercapnia.
Contraindicated Medications: Sedatives, anxiolytics, and hypnotics are strictly contraindicated during acute asthma exacerbations; their respiratory depressant effects precipitate hypercapnic respiratory arrest.
Warning Signs of Impending Respiratory Failure
The "Normal" PaCO2 Paradox: Patients in severe asthma exacerbations hyperventilate due to hypoxemia and bronchospasm, resulting in respiratory alkalosis ( PaCO2 < 35 mmHg ). A normal (40–42 mmHg) or elevated (>45 mmHg) PaCO2 in a visibly tachypneic patient indicates severe respiratory muscle exhaustion, diaphragm fatigue, and impending catastrophic respiratory arrest.
Additional Red Flags: Silent chest on auscultation (insufficient airflow to generate wheezes), diaphoresis, pulsus paradoxus > 20 mmHg, altered mental status (confusion, lethargy), bradycardia, and refractory hypoxemia.
Management of Impending Respiratory Failure: Immediate transfer to the Intensive Care Unit, preparation for rapid sequence intubation (RSI) using ketamine (bronchodilatory properties) and succinylcholine/rocuronium, and mechanical ventilation with low respiratory rate, prolonged expiratory time (I:E ratio 1:3 to 1:4), and low tidal volume (6 mL/kg PBW) to avoid dynamic hyperinflation and tension pneumothorax / auto-PEEP.