Black Nightshade (Solanum nigrum) has a longstanding history in traditional medicine systems, particularly in Ayurveda, Traditional Chinese Medicine, and various folk practices in Africa and South Asia. It has been used for a range of skin conditions, including carbuncles, boils, and other inflammatory lesions. The leaves and sometimes the berries are applied topically as poultices or ointments with the aim of reducing inflammation, drawing out pus, and promoting healing of skin infections such as carbuncles. The rationale in traditional medicine is based on Black Nightshade's purported anti-inflammatory, antimicrobial, and detoxifying properties.

From a scientific standpoint, some laboratory studies indicate that extracts of Solanum nigrum possess anti-inflammatory and antibacterial activities, which could theoretically contribute to the management of bacterial skin infections like carbuncles. However, these effects have mainly been observed in vitro or in animal models, and there is a lack of robust clinical trials in humans to confirm efficacy or safety for this specific use. Therefore, the use of Black Nightshade for carbuncles is primarily justified by traditional knowledge rather than strong scientific evidence.