Skin foxtail millet rash refers to small, raised, solid, and full rashes on the skin. It is as if foxtail millet grains are scattered on the skin, either dispersed individually or clustered together, and can be felt when touched.

This condition is one of the common symptoms in dermatology, but it has not been clearly documented in classical medical texts. Suwen ． Zhizhenyao Da Lun states: "When Shaoyin returns, heat prevails, leading to the disease of rash." The term "rash" here seems to include this condition. Waike Qixuan once pointed out: "A rash is something hidden, appearing and then disappearing, with raised grains that can be felt by hand." This description is slightly more specific than Suwen .

Skin foxtail millet rash is different from general rubella, the "rash" in pediatrics (commonly known as "sha zi"), and the "red rash" and "white rash" in warm diseases. Therefore, the latter three are not within the scope of this discussion.

bubble_chart Pattern Analysis

1. Toxic Heat Invasion︰At the onset, the rash appears red, with spots as small as needle tips or foxtail millet grains. The surrounding area is inflamed, and a single hair runs through the center. Later, the top becomes red and swollen, forming a small pustule. It is accompanied by fever, thirst, dry stools, scanty dark urine, a red tongue with thin yellow coating, and a slippery, rapid pulse. This condition is caused by warm-heat toxins accumulating in the sweat pores. The distinguishing feature of foxtail millet rash is the presence of a hair running through the center, along with redness and a small pustule, making it easy to differentiate from other similar rashes. Treatment involves clearing heat and removing toxins. The recommended internal remedy is the Toxin-Removing Heat-Clearing Decoction, while externally, the Hair Follicle Wash can be applied.
2. Hot Phlegm︰The rash resembles foxtail millet, with large, round, firm grains, a smooth surface, and a reddish hue that turns reddish-brown over time. It is accompanied by mild burning sensations, tidal fever, night sweats, soreness in the lower back and back, insomnia, a red tongue with scant moisture, yellow or greasy coating, and a thready, rapid pulse. It primarily occurs on the face due to lung-kidney yin deficiency, where yin deficiency leads to internal heat, scorching body fluids into phlegm. The interaction of phlegm and heat rises to the face, obstructing the skin and muscles. The rash is round, the size of foxtail millet grains, hard, reddish, and may merge into a raised ridge, accompanied by signs of yin deficiency with internal heat. The treatment principle involves tonifying the lungs and kidneys, clearing heat and resolving phlegm, supplemented by softening hardness. The recommended formula is a modified Fluid-Increasing Decoction combined with Scutellaria and Bulbus Fritillaria Cirrhosae.
3. Wind-dampness Stagnation︰The rash appears purplish-red, flat or polygonal, with a glossy surface, gradually merging into patches that become lichenified, accompanied by intense itching. The tongue is red with thin yellow or slightly greasy coating, and the pulse is wiry and slippery. It commonly occurs on the limbs or trunk but may also affect the mouth, lips, and other areas. This condition arises from the invasion of wind-dampness, failure of dispersion, obstruction in the muscle interstices, and qi stagnation and blood stasis. The rash is flat, polygonal, purplish-red, with a glossy surface, and accompanied by severe itching. The treatment principle involves expelling wind, clearing heat, and removing toxins, supplemented by promoting blood circulation. The recommended formula is Black-Tail Snake Wind-Dispelling Decoction, augmented with Peach Kernel, Carthamus, and India Madder Root.
4. Dampness-heat︰The rash color of foxtail millet is normal or light red, often difficult to distinguish from blisters and erythema, clustered in groups, accompanied by itching, body heat, thirst or thirst without desire to drink, scanty and yellow urine, a red tongue with yellow greasy coating, and a wiry, slippery, rapid pulse. This is due to inherent internal dampness-heat accumulation, compounded by external invasion of dampness-heat pathogenic qi, or consumption of fish, shrimp, seafood, and spicy foods, leading to the binding of internal and external dampness-heat, obstructing and congesting the skin. Foxtail millet rash can occur anywhere on the body but is more commonly seen on the flexural sides of the limbs, often related to damp exposure. The onset is slow, aggravated by eating fish, shrimp, and similar foods, and frequently recurs with noticeable cutaneous pruritus. Treatment focuses on draining dampness and clearing heat, commonly using Gentian Liver-Draining Decoction with modifications.
5. Blood-heat Stagnation in the Skin︰The rash is bright red, resembling the size of foxtail millet grains, sparsely scattered or densely clustered, often appearing alongside erythema and blisters. The skin feels hot and flushed, possibly accompanied by fever, thirst, headache, a red tongue with thin and scant coating, and a slippery, rapid pulse. This condition arises from an inherent yang-heat excess, improper internal or external medication use, leading to dermatitis medicamentosa invading internally, resulting in nutrient-blood heat accumulation and blood heat stagnation in the skin. Foxtail millet-like rashes often occur symmetrically, commonly seen on the oral mucosa, palms, and soles. There is a clear history of medication use, sudden onset, gradual improvement after discontinuation, a relatively short course, mild itching, and notably intense skin burning. Treatment focuses on cooling blood and clearing heat, with Dermatitis Decoction as a potential option.
6. Lung-Stomach Stagnant Heat︰Foxtail millet rash commonly occurs on the face, appearing as foxtail millet grains or mung bean-sized lesions with normal skin color or slight redness and blackheads. When squeezed, a milky-white acne discharge is produced. The skin appears oily, accompanied by bodily heat and discomfort, dry mouth with thirst, dry stools, a red tongue with thin yellow coating, and a slippery, rapid pulse. This is a type of foxtail millet rash frequently seen in adolescents of both sexes, caused by heat in the lung and stomach rising to the face, leading to blood heat stagnation. Clinical features include: foxtail millet rash with slight redness and blackheads, from which acne can be squeezed out, potentially leaving small pitted scars after healing. It primarily affects the face but may also appear on the chest and back. For treatment, clearing and purging lung and stomach stagnant heat is recommended. The prescription Loquat Lung-Clearing Decoction can be modified accordingly, and externally, the Inverted Powder can be applied.

Dampness-heat obstruction foxtail millet rash and blood heat stagnation skin foxtail millet rash: Both syndromes are related to constitution. The foxtail millet rashes in both syndromes are the size of a pinhead or foxtail millet, mixed with small blisters and erythema, making it difficult to differentiate based solely on the rash.

Skin foxtail millet rash often appears alone or may coexist with other skin symptoms. Some foxtail millet rashes remain unchanged for a long time, while others develop into blisters or pustules. Therefore, while mastering the common symptoms and signs of foxtail millet rash, it is also important to pay attention to the different stages of development and changes in the rash, which can be beneficial for improving the level of pattern differentiation and treatment.

bubble_chart Documentation

1. Shoushi Baoyuan: "In ancient times, it was said that measles is like a rash. The rash appears like scattered hemp flowers, while smallpox appears like bean grains, both named after their shapes. The fetal toxin is one. Smallpox originates from the five zang-organs, which belong to yin, and yin governs blood. Therefore, smallpox has form and fluid, and its symptoms include both cold and heat. Measles originates from the six fu-organs, which belong to yang, and yang dominates qi. Therefore, measles has form but no fluid, and its manifestation is mostly solid without cold."