The nose is the Lung’s orifice. When Lung Heat accumulates and stagnates in the Lung channel, it rises along the channel to the nasal passages, producing the clinical cluster that defines Xin Yi Qing Fei Tang’s indication: nasal obstruction with thick yellow-green discharge, reduced sense of smell, nasal dryness, sinus headache, and often concurrent throat dryness and dry cough. Ming Dynasty physician Chen Shigong designed this formula in Wai Ke Zheng Zong specifically for this pattern, applying the principle that clearing the Lung Heat eliminates both the nasal obstruction (by removing the Heat driving Lung-Qi to fail to disperse) and the nasal dryness (by preserving Lung Yin). The classical formula mnemonic — “Xin Yi Qing Fei Yin Huang Qin, Bai He Shan Zhi Zhi Mu Cheng; Mai Dong Gan Cao Shi Gao Deng, Sheng Ma Pi Ye Yi Tong Lun” — encodes all ten herbs and has been transmitted through Yi Zong Jin Jian, Jing Yue Quan Shu, and Yi Fang Ji Jie to reach modern clinical practice.

I. Historical Source and Formula Rationale

Chen Shigong recognised two clinical problems with contemporary treatment of Lung-Heat nasal disease: (1) purely pungent-warm orifice-opening herbs (the instinctive treatment for nasal obstruction) temporarily relieve the blockage but worsen the underlying Lung Heat, causing rapid relapse; (2) purely bitter-cold Lung-Heat-clearing herbs clear the Heat but fail to address Lung-Yin depletion from the Heat, and with sustained use may damage Spleen-Stomach. His solution: combine pungent-warm orifice-opening (Xin Yi) with bitter-cold Heat-clearing (Huang Qin, Zhi Zi, Shi Gao, Zhi Mu) and sweet-cool Yin-nourishing (Mai Dong, Bai He, Pi Pa Ye), with the pungent-warm herb moderated by the cold-clearing herbs and the cold-clearing herbs moderated by Gan Cao. The resulting formula achieves orifice-opening without worsening Heat, and Heat-clearing without damaging Yin — the “clear, open, moisten, and harmonise” four-action formula.

II. Ten-Herb Composition and Formula Analysis

Classic composition from Wai Ke Zheng Zong: Xin Yi (Magnolia bud) · Huang Qin · Zhi Zi · Mai Dong · Bai He · Shi Gao · Zhi Mu · Gan Cao · Pi Pa Ye · Sheng Ma. Modern clinical reference doses: Xin Yi 6–10g (wrapped in gauze) · Huang Qin 10g · Zhi Zi 9g · Mai Dong 12g · Bai He 12g · Shi Gao 20–30g (pre-decoct) · Zhi Mu 9g · Pi Pa Ye 10g · Sheng Ma 6g · Gan Cao 6g. Note: Xin Yi has fine hairs that irritate the throat; it must be wrapped in gauze before decocting.

Chief herb — Xin Yi (Flos Magnoliae) 6–10g (wrapped): pungent, warm; enters Lung, Stomach. Opens nasal orifices and disperses Wind-Cold, promotes the Lung’s dispersing function. Xin Yi is the formula’s primary functional focus — it directly addresses the principal complaint (nasal obstruction) by its pungent aromatic quality penetrating to the nasal mucosa and restoring nasal patency. The Ben Cao Gang Mu records it as “the essential herb for all nasal diseases.” Its warm nature, in the context of this predominantly cold formula, is not a liability but a strategic counterbalance that prevents the bitter-cold herbs from over-suppressing the Lung’s function of warm-dispersion (宣发).

Deputy herbs — Huang Qin, Shi Gao, and Zhi Mu (Lung-Fire clearing triad):

• Huang Qin 10g: bitter, cold; enters Lung, Gallbladder, Spleen. Clears Heat and dries Damp, purges Fire and detoxifies. Specialises in clearing Lung-channel excess Heat — the root cause of nasal Heat-congestion. Its bitter-cold character suppresses the Lung Fire that is driving mucosal inflammation and thick yellow discharge.
• Shi Gao 20–30g (pre-decoct): pungent-sweet, very cold; enters Lung, Stomach. Clears Heat and purges Fire, relieves restlessness and quenches thirst, promotes tissue healing. Shi Gao’s exceptional cold force directly breaks Lung-Stomach excess Heat; its pungent quality also disperses Heat pathogen outward rather than merely suppressing it. Pre-decoct to ensure full extraction of its mineral active components.
• Zhi Mu 9g: bitter-sweet, cold; enters Lung, Stomach, Kidney. Clears Heat and purges Fire, nourishes Yin and moistens Dryness. Zhi Mu’s dual action: it amplifies Huang Qin and Shi Gao’s Lung-Fire clearing while simultaneously nourishing the Lung Yin that the Heat is consuming. This prevents the bitter-cold herbs from creating a net drying effect on the Lung mucosa.

Assistant herbs — Zhi Zi, Mai Dong, Bai He, and Pi Pa Ye:

• Zhi Zi 9g: bitter, cold; enters Heart, Liver, Lung, Stomach, Triple Jiao. Purges Fire and relieves restlessness, clears Heat and disinhibits Damp, cools Blood and detoxifies. Clears residual Fire from the Triple Jiao that supports the Lung-Heat accumulation; its cooling-Blood action addresses the nasal mucosal congestion and epistaxis (nasal bleeding) component of Lung-Heat nasal disease.
• Mai Dong 12g: sweet-slightly cold; enters Lung, Stomach, Heart. Nourishes Yin and generates fluids, clears Lung and Stomach Heat, calms Heart. The primary Yin-protective herb: replenishes Lung-Yin depleted by the sustained Heat, addressing nasal dryness, dry cough, and dry throat that accompany Lung-Heat nasal disease. Pairs with Bai He to form the formula’s Yin-nourishing backbone.
• Bai He 12g: sweet, slightly cold; enters Lung, Heart. Nourishes Yin and moistens Lung, clears Heart and calms Spirit. Amplifies Mai Dong’s Lung-Yin nourishment; also addresses the insomnia and restlessness that sometimes accompany Lung-Heat patterns; together with Mai Dong provides the formula’s essential moistening counterbalance to the bitter-cold drying herbs.
• Pi Pa Ye 10g: bitter, slightly cold; enters Lung, Stomach. Clears Lung Heat and stops cough, descends Qi and harmonises Stomach. Provides additional Lung-Heat clearing alongside the three main clearing herbs; its Qi-descending action also assists Xin Yi in restoring Lung’s normal descending function (impaired in Lung-Heat patterns).

Envoy herbs — Sheng Ma and Gan Cao:

• Sheng Ma 6g: pungent-sweet, slightly cold; enters Lung, Spleen, Stomach, Large Intestine. Clears Heat and detoxifies, raises Yang and disperses. Two roles: (1) guides all herbs upward to the head-face and nasal orifice region, enhancing Xin Yi’s targeting precision; (2) its “fire-venting-by-raising” mechanism (火郁发之) disperses trapped Lung-Heat outward rather than simply suppressing it downward, preventing the “cold-suppression” complication of pure bitter-cold treatment. One and the same ascending principle used in Pu Ji Xiao Du Yin and Qing Wei San.
• Gan Cao 6g: sweet, neutral; harmonises all herbs; moderates Shi Gao and Huang Qin’s extreme cold; moderates Xin Yi’s warm dispersing nature; protects Spleen-Stomach from the formula’s cold-heavy herbs.

Four-action formula design:
① Clear (Huang Qin + Shi Gao + Zhi Mu + Zhi Zi + Pi Pa Ye): clear Lung-Fire and Triple Jiao Heat at the root
② Open (Xin Yi + Sheng Ma): open nasal orifice and guide herbs to head-face; simultaneously vent Fire upward
③ Moisten (Mai Dong + Bai He + Zhi Mu): nourish Lung-Yin depleted by Heat; protect mucosal tissue
④ Harmonise (Gan Cao + strategic warm herbs): prevent cold excess from damaging Spleen-Stomach and Lung-Yang

III. Formula Differentials

IV. Clinical Applications and Modifications

Core pattern: Lung-Heat type nasal disease
Nasal obstruction (bilateral or alternating); thick yellow-green mucopurulent discharge; reduced sense of smell; nasal dryness and burning; frontal or periorbital headache; throat dryness or soreness; dry or productive cough; red tongue with thin yellow coating; floating-rapid or slippery-rapid pulse. No significant chills; no clear thin discharge.

1. Acute and chronic rhinitis (Lung-Heat type): acute bacterial rhinitis with yellow-green discharge and nasal obstruction; chronic rhinitis with recurrent yellow discharge, nasal congestion, and reduced sense of smell — the formula’s primary and classical indication. Modifications: acute infection with prominent Heat-toxin → add Jin Yin Hua 12g, Lian Qiao 9g; chronic with Kidney-Yin deficiency co-pattern → add Nu Zhen Zi 12g, Han Lian Cao 10g.

2. Sinusitis (acute and chronic, Lung-Heat or Damp-Heat type): thick purulent nasal discharge; frontal or maxillary sinus pressure and pain; reduced sense of smell; fever in acute stage. The formula’s Heat-clearing triad (Huang Qin, Shi Gao, Zhi Mu) plus Zhi Zi addresses the inflammatory sinusitis pattern effectively. Modifications: Damp-Heat prominent (heavy greasy feeling, greasy coating) → add Yi Yi Ren 20g, Huo Po 9g; severe headache → add Chuan Xiong 9g, Bai Zhi 9g.

3. Nasal polyps (early stage, Lung-Heat type): classical Chen Shigong indication in Wai Ke Zheng Zong. Early-stage nasal polyps from Lung-Heat accumulation — the formula’s sustained Heat-clearing action may reduce early polyp growth. For established polyps, surgical consultation is required; the formula is an adjunct. Modifications: add Ban Zhi Lian 15g, Bai Hua She She Cao 15g; Phlegm-Stasis component → add Shan Ci Gu 9g.

4. Allergic rhinitis (Heat type with yellow discharge): seasonal allergic rhinitis when the predominant presentation is yellow discharge and nasal Heat rather than clear discharge and cold pattern. Note: purely Wind-Cold allergic rhinitis with clear discharge should use Cang Er Zi San or Yu Ping Feng San, not this formula. Modifications: add Di Long 9g, Wu Mei 12g for anti-allergic action.

5. Atrophic rhinitis and nasal dryness: the formula’s Yin-nourishing component (Mai Dong, Bai He, Zhi Mu) addresses the dry, crusting nasal mucosa of atrophic rhinitis. Modifications: reduce Shi Gao and Huang Qin; add Sha Shen 12g, Tian Hua Fen 12g, Yu Zhu 10g for enhanced Yin-nourishment.

Common modifications:

• Heat-toxin and pus prominent: add Jin Yin Hua 12g, Pu Gong Ying 15g, Zao Xiu 9g
• Nasal bleeding (epistaxis from Lung-Heat): add Bai Mao Gen 15g, Ce Bai Ye 12g, Han Lian Cao 10g
• Sinus headache severe: add Bai Zhi 9g, Chuan Xiong 9g, Man Jing Zi 6g
• Reduced sense of smell prominent: increase Xin Yi to 12g; add Shi Chang Pu 9g
• Spleen-Qi deficiency co-pattern (fatigue, loose stool): reduce Shi Gao and Huang Qin; add Dang Shen 15g, Bai Zhu 12g
• Concurrent Lung-Heat cough with yellow phlegm: add Zhe Bei Mu 9g, Gua Lou 12g; increase Pi Pa Ye

V. Usage, Dosage, and Safety

Preparation: pre-decoct Shi Gao 20–30 min; add Xin Yi wrapped in gauze with remaining herbs; 2 warm doses daily after meals. Patent forms: Hai Tian Xin Yi Qing Fei Tang and Nong Ben Fang Xin Yi Qing Fei Tang.

Contraindications: Wind-Cold nasal disease (clear thin white discharge, chills, white coating, floating-tight pulse) — the formula’s cold-heavy composition will worsen Cold; Spleen-Stomach Cold deficiency with loose stool — reduce Shi Gao and Huang Qin doses significantly; pregnant women (Xin Yi has mild uterine-stimulating properties; use under supervision); allergy to any component. Pattern specificity is essential: this formula is exclusively for Lung-Heat nasal disease. Wind-Cold rhinitis, Qi-deficiency rhinitis, and Kidney-Yang deficiency rhinitis all require different formulas.

Lifestyle co-treatment: avoid spicy, oily, and heat-generating foods; avoid smoking and passive smoke; maintain nasal hygiene (saline nasal rinse can complement formula action); adequate sleep; reduce air pollution exposure; avoid allergen triggers in allergic rhinitis.