**Core Concept**
Impetigo is a highly contagious bacterial skin infection caused by Staphylococcus aureus or Streptococcus pyogenes. It typically presents as red, indurated, and tender lesions with a characteristic "golden crust" that can progress to deeper tissue involvement, including cellulitis and abscesses.

**Why the Correct Answer is Right**
The child's symptoms of redness, induration, and tenderness around the injury site, combined with a fever of 39.4°C, are indicative of a severe bacterial infection. Given the potential for rapid progression to deeper tissue involvement, including abscesses and cellulitis, prompt and aggressive management is necessary. Surgical debridement is crucial to remove infected tissue and promote healing, while antibiotic treatment is essential to address the underlying bacterial infection. In this case, immediate admission to the hospital for close monitoring and treatment is the most appropriate response.

**Why Each Wrong Option is Incorrect**
**Option A:** Arranging for a plastic surgery consultation at the next available appointment is not appropriate in this scenario, as the child's symptoms suggest a severe bacterial infection that requires immediate attention, not a cosmetic consultation.

**Option C:** Prescribing penicillin over the telephone and having the mother apply warm soaks is not sufficient, as it may not address the underlying severity of the infection, and warm soaks can potentially worsen the condition by promoting bacterial growth.

**Option D:** Suggesting the purchase of bacitracin ointment is not an adequate response, as it is a topical antibiotic that may not penetrate deep enough to address the underlying infection, and it does not address the need for surgical debridement.

**Clinical Pearl / High-Yield Fact**
In cases of suspected bacterial skin infections, it is essential to consider the possibility of deeper tissue involvement, such as cellulitis or abscesses, and to manage these patients aggressively with surgical debridement and antibiotic treatment.

**✓ Correct Answer: B. Admit the child to the hospital immediately for surgical debridement and antibiotic treatment.**