Examkin

Question

Difficulty: MediumInfectious Diseases

Select the most appropriate first-line antimicrobial therapy for each of the following patient presentations.

  • During a routine obstetric visit, a woman at 10 weeks gestation is evaluated for an 8-cm expanding annular erythematous rash with central clearing. She recently returned from a camping trip in New York.Oral amoxicillin
  • An adult male seeks evaluation at a sexual health clinic for a single, painless, indurated penile ulcer with a clean base. His rapid plasma reagin testing returns reactive.Intramuscular penicillin G benzathine
  • While undergoing induction chemotherapy for acute myeloid leukemia, a hospitalized patient develops a fever of 38.9°C (102.0°F). Laboratory testing shows an absolute neutrophil count of 200/mm³.Intravenous cefepime
  • An untreated patient with advanced HIV (CD4 count 35/mm³) reports progressive blurring of vision and floaters. Ophthalmic examination reveals perivascular yellow-white retinal exudates with associated hemorrhages.Oral valganciclovir
  • A patient with HIV (CD4 count 80/mm³) complains of worsening retrosternal pain upon swallowing. Physical examination reveals removable white plaques on the buccal mucosa.Oral fluconazole

Answer

The clinical scenarios correctly match with their targeted antimicrobial therapies: early Lyme disease in pregnancy with oral amoxicillin, primary syphilis with intramuscular penicillin G benzathine, febrile neutropenia with intravenous cefepime, CMV retinitis with oral valganciclovir, and esophageal candidiasis with oral fluconazole.
Each specific clinical syndrome corresponds to a singular first-line, evidence-based antimicrobial therapy. Amoxicillin prevents teratogenic complications in pregnant patients with Lyme disease. Intramuscular penicillin G benzathine is the only proven reliable curative agent for primary syphilis. Intravenous cefepime provides the necessary empiric antipseudomonal coverage for febrile neutropenia. Oral valganciclovir offers targeted cytomegalovirus inhibition for CMV retinitis. Oral fluconazole provides systemic coverage necessary for esophageal candidiasis.

Step-by-Step Solution

1
Analyze the pregnant patient with an annular rash following a camping trip in an endemic region.
Diagnosis is early localized Lyme disease. The preferred treatment in pregnancy is oral amoxicillin.
Standard doxycycline therapy is contraindicated in pregnancy due to risks to fetal bone and teeth development.
2
Evaluate the patient with a painless penile ulcer and reactive RPR.
Diagnosis is primary syphilis, which is definitively treated with intramuscular penicillin G benzathine.
This depot formulation provides the sustained treponemicidal levels necessary for cure.
3
Assess the chemotherapy patient presenting with fever and an absolute neutrophil count < 500/mm³.
Diagnosis is high-risk febrile neutropenia, necessitating intravenous cefepime.
Immediate empiric broad-spectrum coverage with antipseudomonal activity is required to prevent rapid clinical deterioration.
4
Examine the advanced HIV patient with floaters, retinal hemorrhages, and exudates.
Diagnosis is CMV retinitis, treated specifically with oral valganciclovir.
Targeted anti-CMV therapy is required to prevent blindness.
5
Identify the cause of odynophagia in the HIV patient with concurrent oral thrush.
Diagnosis is esophageal candidiasis, which responds effectively to oral fluconazole.
Topical antifungals are insufficient for esophageal involvement; systemic therapy is required.

Key Concept

Targeted Antimicrobial Selection for Common Infectious Syndromes
Rate this question

Topics

Infectious Diseases

More questions from this topic