Pinellia (Pinellia ternata), known as "Ban Xia" in Traditional Chinese Medicine (TCM), has a long history of use for treating respiratory conditions, including sinus congestion and sinusitis. In TCM, it is classified as a herb that transforms "phlegm" and dries dampness, often used in various classical formulas to address symptoms such as nasal congestion, cough with phlegm, and a sensation of fullness in the sinuses or chest. Common formulas containing Pinellia include Er Chen Tang and Ban Xia Hou Po Tang, both of which are traditionally used to clear phlegm and relieve upper respiratory symptoms.

The rationale for using Pinellia in sinus infections is primarily based on these traditional concepts rather than modern biomedical evidence. While preclinical studies have shown that Pinellia contains bioactive compounds with anti-inflammatory and expectorant properties, there is a lack of robust clinical trials specifically examining its efficacy for sinus infections (rhinosinusitis) in humans. Most of the available evidence comes from historical texts and case reports within the TCM literature. Therefore, while its use is well-established in traditional practice, scientific validation remains limited.