ID Cases

Cases

Master Infectious Diseases boards through clinical cases, diagnostic reasoning, and high-yield syndrome review.

Latest Cases

Recent cases from IDHub

104 of 104 cases shownNewest first

Case

The Persistent Burn

Persistent urethritis in a young man after standard GC/CT treatment, with questions on microbiology, NAAT methodology, and resistance-driven sequential therapy.

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The Winter Breakthrough

Severe influenza A after allogeneic HSCT, with questions on viral entry, oseltamivir, and prevention.

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The Unyielding Ring

Ring-enhancing brain lesions in an HIV patient from Bolivia that fail empiric toxoplasmosis therapy.

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The Mulberry Wound

A progressive granular nasal ulcer in a Venezuelan coffee farmer.

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The Waning Shield

A hemodialysis patient with MRSA bacteremia who fails to clear blood cultures on vancomycin — and the mechanism behind it.

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The Brainstem Under Siege

A rituximab-treated adult in Vietnam with brainstem encephalitis, myoclonus, and a characteristic MRI pattern after contact with hand-foot-and-mouth disease.

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What Grew in the Scar

A retired gold miner with progressive massive fibrosis develops constitutional symptoms and a new right upper lobe cavitary lesion on CT.

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A Firestorm After the Cure

A man from the Peruvian Amazon develops abrupt fever, painful nodular crops, neuritis, and orchitis several months after completing multidrug therapy for multibacillary leprosy.

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Fever in the Ozarks

A deer hunter from rural Missouri presents with four days of fever, leukopenia, thrombocytopenia, and transaminitis after removing ticks from his legs.

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The Long Sleep

A humanitarian aid worker presents with cyclical fevers six months after returning from Papua New Guinea despite completing her malaria prophylaxis correctly.

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The Absent Shield

A previously healthy Vietnamese-born woman presents with four months of fevers, weight loss, and massive lymphadenopathy. HIV is negative and CD4 is normal.

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Quiet Enzymes

A kidney transplant recipient on tacrolimus presents with asymptomatic transaminase elevation and a dietary exposure that points away from the usual suspects.

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The Wrong Host

A young man with extensive tropical travel and dog shelter exposure presents with eosinophilia, hepatic lesions, pulmonary infiltrates, and a persistently negative stool exam.

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The Rough Colony

A young man with cystic fibrosis develops progressive pulmonary infiltrates, constitutional symptoms, and subcutaneous nodules five months after bilateral lung transplantation.

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Before Day Forty-Two

A woman with AML develops focal neurological deficits and confusion on day thirteen after allogeneic bone marrow transplantation, before prophylaxis has been started.

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The Fig Tree Fever

A Los Angeles resident develops nine days of fever, headache, and a subtle truncal rash after exposure to cats and backyard wildlife.

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After the Lithotripsy

Bacteremic difficult-to-treat Pseudomonas after urinary instrumentation and residual stone burden.

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The Normal Lung Exam

A young patient develops progressive breathlessness with little to hear on lung exam.

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The Hike and the Tender Node

A camper in California's Sierra Nevada develops fever and a painful inguinal node after a small bite near the ankle.

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Fever after the Coffee Farms

A traveler returning from coffee farms in Tolima, Colombia develops fever, early jaundice, thrombocytopenia, and transaminitis.

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The Negative Test and the Worsening Lungs

An immunosuppressed patient develops progressive multilobar pneumonia despite standard therapy and an initially reassuring test result.

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The Ulcers That Would Not Heal

A stem cell transplant recipient develops progressive mucocutaneous ulceration despite standard antiviral therapy.

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The New Infiltrates on Week Three

A patient receiving outpatient therapy for MRSA bacteremia returns with fever, hypoxemia, and new bilateral pulmonary infiltrates.

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The Gardener's Finger

A gardening injury that did not behave like routine cellulitis.

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The Painful Mouth and the Quiet Lungs

A young woman with severe oral mucositis, minimal skin disease, and subtle pulmonary findings.

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When the Back Pain Came Late

A man develops delayed lumbar pain and constitutional symptoms long after intravesical BCG for urothelial carcinoma. Biopsy reveals granulomatous vertebral infection, and the next step depends on reading the clues correctly.

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When Ceftriaxone Fails

A cirrhotic patient develops persistent VRE bacteremia despite standard ceftriaxone prophylaxis, illustrating why Enterococcus faecium must be interpreted differently from Enterococcus faecalis.

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The Ring in the Right Upper Lobe

A patient with uncontrolled diabetes and diabetic ketoacidosis has a right upper lobe reverse halo sign on chest CT.

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After the Headaches Faded

A patient with advanced HIV develops worsening focal deficits and a left frontal white matter lesion with midline shift after ART initiation.

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Fever and Arthralgia after Caribbean Travel

A traveler returning from the Dominican Republic presents with fever, severe polyarthralgia, and rash. Diagnose and manage this arboviral infection.

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Heart Failure from the Andes

A Colombian immigrant presents with progressive heart failure and characteristic cardiac findings.

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The Shoulder That Wouldn't Heal

Subtle signs and a revealing gram stain lead to the diagnosis of an unusual shoulder infection. Master the key learning points for managing similar cases.

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The 5-Month Mystery

A new murmur and persistent fevers follow heart surgery.

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The Silent Swallow

When aspiration writes a prescription for the brain.

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The Forgotten Toe

A diabetic foot ulcer that wouldn't heal, leading to osteomyelitis and amputation.

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The Sweet Smell of Trouble

Fever, weight loss, and a multiloculated liver abscess — with a blood culture plate that smells like butterscotch.

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The Loyal Companion

Septic shock and meningitis in an asplenic patient whose dog never bit her.

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Fever From the Forest

Fever, rash, and a painless black-crusted ulcer after trekking in rural Nepal.

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Paresthesias in Paradise

Severe headache, migratory paresthesias, and a CSF full of eosinophils after a Hawaiian farm dinner.

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After the Extraction

Acute knee pain in a patient with a prosthetic joint after a dental procedure.

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The Cellulitis That Kept Coming Back

Recurrent leg swelling, a healing inguinal scar, and a blood draw that had to wait until midnight.

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Two Continents, One Smear

Fever, hemolysis, and intraerythrocytic ring forms in an asplenic traveler.

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Lights Out on Postoperative Day 21

Seizure and cortical blindness in a kidney transplant recipient on tacrolimus.

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The Fever That Would Not Wait

TB meningitis in a newly diagnosed HIV patient — treatment timing and ART selection.

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The Plaque Before the Storm

A facial skin lesion that foreshadowed a fatal encephalitis.

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The Breast Mass That Wasn’t Cancer

A suspicious breast mass with a hidden microbiologic cause.

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The Rainy Season Abscess

A diabetic farmer, a draining wound, and a dangerous saprophyte.

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A Shot in the Dark

Choosing the right ART when prevention was an injection.

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Soft Edges and a Swollen Groin

A painful genital ulcer that resists easy categorization.

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The Traveling Edema

Migratory edema after raw seafood exposure.

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Desert Screening Dilemma

An HIV follow-up case.

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When the Fever Breaks

A tropical febrile illness takes a dangerous turn.

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Follicles Beneath the Upper Lid

Chronic conjunctivitis in a child from rural Ethiopia.

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Recurrent Pneumococcemia

Recurrent invasive pneumococcal disease with a subtle hematologic clue.

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Progressive Spastic Paraparesis in a Woman from Guyana

A tropical differential for myelopathy.

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Persistent Diarrhea and Flatulence After Travel to India

Greasy stools, bloating after dairy, and a classic travel-related cause of persistent diarrhea.

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Fever During Alemtuzumab Therapy

An opportunistic infection clue during lymphocyte-depleting therapy.

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Postpartum Fever, Diplopia, and Hemiparesis

A stroke-mimic presentation of postpartum brainstem infection.

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New HIV Diagnosis in a Patient on Hemodialysis

Selecting initial ART in end-stage kidney disease on dialysis.

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Symmetric Groin Plaques in a Man With Diabetes

An intertriginous rash with a key bedside clue.

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Acute Dysentery in a Returning Aid Worker

A high-yield cause of acute bloody diarrhea.

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Severe Hypertension and Renal Failure in Western Mozambique

A tropical cause of bilateral obstructive uropathy and renal failure.

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Jaw Stiffness in a Visitor from Rural Haiti

An early neurologic warning sign with a dangerous trajectory.

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Transient Leg Weakness in a Man from Rural Colombia

Transient deficits, basal cistern lesions, and a hidden tropical diagnosis.

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Persistent Fever, Splinter Hemorrhages, and an Aortic Valve Abscess

A culture-negative endocarditis clue hiding in the exposure history.

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Verrucous Skin Lesions and a Right Upper Lobe Cavitary Opacity

A verrucous arm lesion, diagnostic GMS stain, and right upper lobe pulmonary disease.

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The Climbing Lesion

Not your routine skin and soft tissue infection.

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After the Steroid Burst

ICU shock, pulmonary infiltrates, and diarrhea after immunosuppression.

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A Cheesy Clue

Infectious differential for chronic diarrhea and edema.

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The Case of the Returning Fever

Recurrent fever, jaundice, and a diagnosis hiding in the clothing seams.

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At the Tip of the Nose

A unilateral facial eruption with ocular risk and a misleading early course.

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Fever, Hemolysis, and Bleeding Papules After Andes Travel

A classic biphasic Bartonella bacilliformis syndrome.

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Slowly Progressive Lumbar Mass

When a soft-tissue mass is an indolent infection.

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Chronic Hemoptysis in a Traveler from Rural Colombia

When lung flukes mimic TB.

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A Cryptic Case

When CNS cryptococcosis reveals an acquired immune defect.

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Fulminant Shock

Shock in the Slaughterhouse

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Fever and Cytopenias After Heart Transplant

When the Marrow Goes Quiet

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Headache, Ataxia, and Sixth Nerve Palsy in Connecticut

Brief attachment

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When molluscum is not molluscum

Another skin lesion...

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A Nose Lesion that Wouldn’t Heal

A chronic nasal lesion with a broad differential diagnosis.

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Amazon Adventure

A returning traveler lesion.

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Bloody Diarrhea Without a Clear Cause

An unexpected culprit.

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Fever, Urinary Symptoms, and a Heart Murmur

Beyond the obvious: Gram-positive clusters.

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Hundreds of Lesions

Neglect, poverty, and a devastating skin disease.

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A Dangerous Predilection

A man with a known aortic aneurysm, a forgotten diarrheal illness, and blood cultures that explain everything.

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A Quiet Invasion

A returning traveler with RUQ pain, fever, and a hypodense hepatic lesion — and no culturable bacteria.

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A Stubborn Course

A kidney transplant recipient who completed C. diff treatment but keeps getting worse — the biopsy reveals who was really behind it.

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Fever after Floodwaters

A rice farmer presents with fever, jaundice, and renal failure after wading through floodwaters.

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Forgotten but Not Gone

An unvaccinated adult with bacterial meningitis and a Gram stain that tells the whole story.

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Hidden in Plain Sight

A patient with newly diagnosed HIV, a CD4 of 18, and a bone marrow that told the whole story.

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Memory Lost

A post-BMT patient with progressive amnesia, seizures, and a viral PCR result that demands a second look.

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Not the Cat's Fault

A South Texas woman with cats, a flea, and a fever that didn't need a tick to get started.

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Positive, But Wrong

A neutropenic BMT recipient with a positive CrAg and skin lesions that pointed elsewhere.

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Resistance by Default

Not all vancomycin resistance is created equal.

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The Blinding Cycle

A community health worker in rural Ethiopia with bilateral eye irritation and follicles on the upper tarsal conjunctiva — the world's leading infectious cause of blindness.

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The Copper Penny Sign

A Brazilian farmer with a 3-year verrucous plaque and a pathognomonic tissue finding.

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The Eye of the Rabbit

A hunter from Arkansas who field-dressed a rabbit without gloves now has a red eye, a golf ball-sized preauricular node, and a corneal ulcer that is not pink eye.

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The Great Imitator

A rash that reaches the palms and a genital sore the patient thought had healed.

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The Indeterminate Answer

A man with newly diagnosed HIV and a CD4 of 118 whose household partner has pulmonary TB — and a QuantiFERON result that demands careful interpretation.

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The Long Way Home

A humanitarian aid worker returning from the DRC with progressive neuropsychiatric symptoms and a blood smear that tells the whole story.

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The Mass at Twelve Months

A heart transplant recipient with fever, night sweats, and a left upper lobe mass one year after transplant.

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The Viscous Clue

A diabetic man with endophthalmitis whose blood cultures revealed more than an eye infection.

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The Watercress Fever

A Bolivian immigrant with fever, eosinophilia, and hepatic migratory lesions.

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The Wheel Turns

A nosocomial gastroenteritis outbreak on a surgical ward and a virus whose structure changes everything about how you contain it.

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Created by Alvaro Ayala, MD

Infectious Diseases Fellow at Stanford University, building a clearer, more useful home for case-based learning and clinical reasoning in ID.

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