15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

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

15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

Key Takeaways Explain This Topic AI

Allergic rhinitis, acute and chronic sinusitis, allergic conjunctivitis and upper airway cough syndrome are enumerated under rhinitis, sinusitis and conjunctivitis.

Mastocytosis, allergic interstitial nephritis, eosinophilic esophagitis, eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis and hypersensitivity pneumonitis are enumerated under autoimmune systemic disorders.

Intranasal corticosteroids are the most effective single therapy for allergic rhinitis and outperform oral antihistamines.

Systemic mastocytosis is suggested by an elevated baseline serum tryptase with flushing, anaphylaxis and gastrointestinal symptoms.

IgG4-related disease produces tumefactive lesions in multiple organs including autoimmune pancreatitis, retroperitoneal fibrosis and salivary gland enlargement.

Last updated: August 2026

1. Allergic Rhinitis

IgE-mediated inflammation of the nasal mucosa: sneezing, clear rhinorrhea, nasal congestion and itching of the nose, eyes and palate , with pale boggy turbinates, allergic shiners and a transverse nasal crease.

Classification by pattern (intermittent versus persistent) and severity guides treatment.

Therapy in evidence order:

Therapy Comment

Intranasal corticosteroid Most effective single agent ; superior to oral antihistamines for congestion and overall symptoms; takes days to reach full effect

Second-generation oral antihistamine Useful for sneezing, itching and rhinorrhea; less effective for congestion

• Intranasal antihistamine Rapid onset; can be combined with intranasal steroid
• Leukotriene receptor antagonist Less effective; neuropsychiatric warnings limit use
• Allergen immunotherapy Disease-modifying , with benefit persisting after completion
• Allergen avoidance Logical but often impractical for aeroallergens

Do not use intranasal decongestants for more than a few days — rhinitis medicamentosa (rebound congestion) follows, and it is a common cause of refractory congestion that resolves only with withdrawal.

Non-allergic rhinitis — vasomotor rhinitis triggered by temperature change, odors and alcohol; gustatory rhinitis; and drug-induced rhinitis from ACE inhibitors, alpha-blockers, beta-blockers, NSAIDs and oral contraceptives — mimics allergic rhinitis but lacks itching and sneezing and is not IgE-mediated.

Unilateral symptoms are a red flag : unilateral obstruction, purulent or bloody discharge, or facial pain suggests a foreign body, tumor, polyp, or cerebrospinal fluid rhinorrhea (clear fluid positive for beta-2 transferrin).

2. Sinusitis

Most acute sinusitis is viral and resolves without antibiotics. The clinical features that support acute bacterial rhinosinusitis are:

• Symptoms persisting 10 days or more without improvement
• Severe symptoms — high fever with purulent discharge and facial pain — for at least 3 to 4 consecutive days
• Double worsening — initial improvement followed by deterioration

Amoxicillin-clavulanate is first-line when antibiotics are indicated. Watchful waiting with symptomatic care is appropriate in many patients.

Complications requiring urgent imaging: periorbital or orbital swelling, visual change or ophthalmoplegia (orbital cellulitis or abscess), severe headache with altered mental status (intracranial extension), or Pott puffy tumor (frontal bone osteomyelitis).

Chronic rhinosinusitis lasting 12 weeks or more is subclassified by the presence of nasal polyps , and polypoid disease should prompt consideration of aspirin-exacerbated respiratory disease , cystic fibrosis (particularly in a younger adult), and eosinophilic granulomatosis with polyangiitis .

Invasive fungal sinusitis — in a diabetic patient with ketoacidosis or a neutropenic patient, facial pain with a black eschar on the palate or turbinates is mucormycosis and is a surgical emergency.

3. Conjunctivitis and Upper Airway Cough Syndrome

Allergic conjunctivitis produces bilateral itching, tearing, conjunctival injection and chemosis, typically with rhinitis, and is treated with topical antihistamine-mast cell stabilizers. Itching is the cardinal symptom — its absence should make you doubt an allergic cause.

Upper airway cough syndrome is an enumerated topic and the most common cause of chronic cough in a non-smoker with a normal chest radiograph. Postnasal drainage and throat clearing with cobblestoning of the posterior pharynx; diagnosis is confirmed by response to an empiric first-generation antihistamine-decongestant , whose anticholinergic properties are part of the mechanism — second-generation agents are less effective for this indication.

4. Atopic and Contact Dermatitis

Skin disorders is an enumerated subsection under Allergy and Immunology listing atopic dermatitis and contact dermatitis .

• Atopic dermatitis Allergic contact dermatitis Irritant contact dermatitis
• Mechanism Barrier dysfunction plus type 2 inflammation Type IV delayed hypersensitivity Direct chemical injury

Distribution Flexural in adults; face and extensors in infants Pattern of exposure , sharply demarcated Site of contact

• Timing Chronic, relapsing 24 to 72 hours after exposure Minutes to hours
• Testing Clinical Patch testing Clinical

Patch testing, not skin prick testing, diagnoses allergic contact dermatitis — a distinction the exam uses, since prick testing detects IgE-mediated sensitization and contact dermatitis is T-cell mediated. Common contact allergens include nickel , fragrance, preservatives, rubber accelerators, topical antibiotics (neomycin, bacitracin) and poison ivy urushiol.

Atopic dermatitis management: emollients, topical corticosteroids matched to site, topical calcineurin inhibitors and JAK inhibitors for sensitive areas, and biologics for severe disease. Recognize eczema herpeticum — abrupt monomorphic punched-out vesicles and erosions with fever in a patient with atopic dermatitis — as a dermatologic emergency requiring systemic acyclovir.

5. Mastocytosis and Mast Cell Disorders

Enumerated under autoimmune systemic disorders (including IgG4-related disorders) .

Systemic mastocytosis results from clonal mast cell proliferation, usually driven by a KIT D816V mutation.

Clinical clues:

Recurrent flushing, pruritus, hypotension and unexplained anaphylaxis , particularly severe reactions to hymenoptera stings

• Urticaria pigmentosa — reddish-brown macules that urticate when stroked (Darier sign)
• Abdominal pain, diarrhea, peptic ulceration
• Unexplained osteoporosis in a young person
• Hepatosplenomegaly and cytopenias in aggressive forms

Diagnosis: elevated baseline serum tryptase (measured at least 24 hours after any acute event, since tryptase rises transiently in anaphylaxis), followed by bone marrow biopsy with KIT mutation testing and CD25 expression.

Triggers to avoid: hymenoptera stings, opioids, radiocontrast, NSAIDs, alcohol, temperature extremes, and physical stimuli. Every patient should carry an epinephrine autoinjector.

Hereditary alpha-tryptasemia is a common cause of a modestly elevated baseline tryptase from increased TPSAB1 gene copy number, and must be distinguished from clonal mast cell disease.

6. The Eosinophilic Organ Diseases

The blueprint groups several eosinophil-driven conditions in this subsection, and they are unified by tissue eosinophilia with variable peripheral eosinophilia.

Disease Presentation Key point

Eosinophilic esophagitis Dysphagia, food impaction in an atopic young adult Diagnosed by esophageal biopsy despite normal-appearing mucosa; treated with proton pump inhibitor, topical swallowed steroid, diet, or dupilumab

Eosinophilic pneumonia Acute: fever and hypoxemic respiratory failure over days, often in a new smoker. Chronic: subacute cough, dyspnea, weight loss with peripheral (reverse pulmonary edema) infiltrates Both respond dramatically to corticosteroids; chronic form relapses on taper

Allergic (acute) interstitial nephritis Rising creatinine, sterile pyuria, white cell casts after a drug Drug withdrawal is primary; PPIs and NSAIDs are common culprits

Eosinophilic granulomatosis with polyangiitis Asthma plus eosinophilia plus vasculitis Neuropathy (mononeuritis multiplex), cardiac involvement drives mortality; MPO-ANCA in a minority

Hypersensitivity pneumonitis Cough and dyspnea after antigen exposure — birds, mold, hot tubs, farm work Antigen identification and removal is the essential treatment

Before attributing eosinophilia to an allergic cause, exclude parasitic infection and drug reaction. Strongyloides must be excluded before corticosteroids in anyone with relevant exposure, because immunosuppression precipitates fatal hyperinfection syndrome.

Marked persistent eosinophilia above 1,500 per microliter with organ damage defines hypereosinophilic syndrome and requires evaluation for a clonal myeloid disorder.

7. IgG4-Related Disease

Explicitly named in the blueprint subsection heading. A fibroinflammatory condition producing tumefactive lesions — mass-like swellings that mimic malignancy — across multiple organs, typically in middle-aged and older men.

Organ manifestations that should trigger the thought:

Organ Manifestation

Pancreas Autoimmune pancreatitis (type 1) — a painless obstructive jaundice with a pancreatic mass that mimics carcinoma

• Biliary tree IgG4-related sclerosing cholangitis
• Salivary and lacrimal glands Painless submandibular and lacrimal enlargement (formerly Mikulicz disease)
• Retroperitoneum Retroperitoneal fibrosis with ureteral obstruction
• Kidney Tubulointerstitial nephritis
• Aorta Inflammatory aortitis and periaortitis
• Orbit Orbital pseudotumor
• Lung Nodules, interstitial disease

Characteristic features: an elevated serum IgG4 (which is neither sensitive nor specific — it is normal in a substantial minority and elevated in other conditions), frequent allergic history and peripheral eosinophilia , and biopsy showing a dense lymphoplasmacytic infiltrate with storiform fibrosis, obliterative phlebitis and abundant IgG4-positive plasma cells .

The clinical importance is twofold: it is repeatedly mistaken for malignancy, leading to unnecessary resection — most notably the Whipple procedure performed for what proves to be autoimmune pancreatitis — and it responds dramatically to corticosteroids , with rituximab used for relapsing disease.