Tea tree oil (Melaleuca alternifolia) is an essential oil that has been traditionally used in Australian Aboriginal medicine for its antimicrobial properties. In recent decades, its use has extended to various skin infections, including boils and carbuncles, due to its broad-spectrum antibacterial and anti-inflammatory actions. Laboratory studies have demonstrated that tea tree oil is effective against Staphylococcus aureus, including some methicillin-resistant strains (MRSA), which are common pathogens in carbuncles. The primary active component, terpinen-4-ol, is believed to disrupt bacterial cell membranes and inhibit microbial growth.

However, clinical evidence specifically evaluating tea tree oil for the treatment of carbuncles is limited. Most studies involve its use in minor skin infections or as an adjunct in wound care, and are often small-scale or lack rigorous controls. Case reports and small trials suggest that topical tea tree oil may help reduce bacterial load and inflammation, potentially promoting healing in superficial skin abscesses. Adverse effects such as skin irritation and allergic reactions have been noted, and tea tree oil should never be ingested.

In summary, while laboratory and limited clinical data support the potential benefits of tea tree oil for skin infections like carbuncles, high-quality clinical trials are lacking. Its use is thus grounded in both scientific plausibility and limited clinical evidence, meriting a moderate evidence rating.