Antibiotic-Associated Diarrhea in a 4-Year-Old with Infected Mosquito Bites
Case at a Glance
A 4-year-old girl with known allergic sensitivities developed severe diarrhea while on amoxicillin therapy for infected mosquito bites, raising concerns about antibiotic-associated adverse effects and appropriate treatment duration.
Patient's Story
A 4-year-old female patient (weight: 36 lbs) with a medical history of anaphylactic egg allergy and significant reactions to mosquito bites presented with infected mosquito bite lesions. The patient was prescribed amoxicillin 4.4ml twice daily for 10 days and topical hydrocortisone 2.5%/mupirocin 2% twice daily for 7 days. Family history was notable for maternal allergy to amoxicillin. On day 2 of antibiotic therapy, the patient began experiencing diarrhea that progressively worsened. By day 7, she required return to diapers despite being toilet-trained for one year, experienced fecal incontinence, and developed abdominal pain with nocturnal awakening and distress. The original mosquito bite inflammation had resolved by this time.
Initial Assessment
Physical examination revealed infected mosquito bite lesions with surrounding erythema, warmth, and swelling. The patient was afebrile and otherwise well-appearing. Given the patient's history of significant allergic reactions and family history of amoxicillin allergy, antibiotic therapy was initiated with close monitoring.
The Diagnostic Journey
The patient's progressive gastrointestinal symptoms raised several diagnostic considerations: antibiotic-associated diarrhea, possible allergic reaction to amoxicillin (given family history), or Clostridioides difficile infection. The timing of symptom onset coinciding with antibiotic initiation and progressive worsening suggested drug-related etiology.
Final Diagnosis
Antibiotic-associated diarrhea secondary to amoxicillin therapy, with complete resolution of the original skin infection by day 7 of treatment.
Treatment Plan
Discontinuation of amoxicillin was recommended given resolution of the original infection and significant gastrointestinal adverse effects. Supportive care with adequate hydration and dietary modifications were advised. Close monitoring for symptom resolution was planned.
Outcome and Follow-up
Following antibiotic discontinuation, the patient's diarrhea gradually resolved. The infected mosquito bites remained healed without recurrence. This case highlighted the importance of reassessing antibiotic necessity when adverse effects occur, particularly when the original indication has resolved.