This paper summarizes clinical experience in treating acne based on the staged therapeutic principles of "eruption in warm diseases

". It is considered that acne results from wind-heat retained in the lungs， invading the

ying

level and obstructing the blood collaterals， and is primarily a disorder involving both the

wei

and

ying

systems. In clinical practice， the treatment emphasizes the use of acrid-cool and sweet-cold methods. The core prescription is namely

Yinqiaosan Qu Douchi Jia Xishengdi Danpi Daqingye Bei Xuanshen Fang

（from

Epidemic Warm Diseases

［《温病条辨》］）， and is adjusted according to the stage of disease. In the non-inflammatory stage， when the pathogen initially attacks the

wei

level， treatment focuses on acrid-cool herbs to release the exterior， with supplementary bitter-sweet ingredients such as Yejuhua （

Chrysanthemum Indicum

）. In the inflammatory stage， with pronounced heat toxin in the

qi

level affecting the

ying

and blood， and local stagnation of

qi

and blood， the approach is to clear heat and resolve toxin， using blood-cooling and stasis-resolving herbs early to prevent progression. Herbs such as Pugongying （

Taraxacum Mongolicum

）， Zihuadiding （

Viola Yedoensis

）， Tiankuizi （

Semiaquilegia Adoxoides

）， Chonglou （

Paris Polyphylla

）， Machixian （

Portulaca Oleracea

）， Zaojiaoci （

Gleditsia Sinensis

）， Chuanshanjia （

Manis Pentadactyla

） may be added. In the post-inflammatory erythema stage， when

yin

of the

ying

level is depleted and internal deficiency-heat arises， sweet-cold herbs are recommended to nourish the stomach and generate fluids， with the possible addition of

Yiwei Decoction

（益胃汤）.