A 29-year-old woman comes to the emergency department complaining of painful genital ulcers that have been present for 4 days as well as low-grade fever and malaise. She denies any recent travel, new sexual partners, or antibiotic use. Physical examination reveals multiple clustered vesicles and shallow ulcers in the vulvar region. A Tzanck smear shows multinucleated giant cells. Which of the following medications is most appropriate for treating her condition?
Acyclovir
Amoxicillin
Fluconazole
Trimethoprim-sulfamethoxazole
Acyclovir
The patient's painful genital ulcers coupled with the presence of multinucleated giant cells on a Tzanck smear are indicative of a herpes simplex virus type 2 (HSV-2) infection. Acyclovir is the treatment of choice.

Herpes infections can present with painful genital ulcers and low-grade fever. The Tzanck smear showing multinucleated giant cells further confirms the diagnosis though the diagnosis is typically made on clinical grounds and treated empirically. Acyclovir is the drug of choice for treating HSV-2 as it inhibits viral DNA polymerase, preventing the virus from replicating. The drug can reduce the duration and severity of symptoms but does not eradicate the virus entirely.

Groves (2016) emphasizes that genital herpes, caused by the herpes simplex virus (HSV), affects over 400 million people worldwide. The infection is lifelong, with vesicular outbreaks in genital areas that can ulcerate. While HSV-1 and HSV-2 are both culprits, the latter increases the risk of HIV acquisition. The polymerase chain reaction assay is the recommended diagnostic method. Nucleoside analogues are effective treatments, and pregnant women with the condition are advised antiviral prophylaxis from the 36th week until delivery to prevent neonatal complications.

Incorrect Answers:
Answer B: Amoxicillin is an antibiotic ineffective against viral infections like HSV-2. It is commonly used for bacterial infections such as streptococcal pharyngitis.

Answer C: Fluconazole is an antifungal agent is used for treating fungal infections like Candida which may cause esophagitis or vaginitis.

Answer D: Metronidazole is used primarily for anaerobic bacterial and protozoal infections.

Answer E: Trimethoprim-sulfamethoxazole is used for bacterial infections like urinary tract infections and also offers MRSA coverage.

Bullet Summary:
Acyclovir is the drug of choice for treating herpes simplex virus infections.