Cholinergic Urticaria and 'Heat'

Cholinergic urticaria. The name sounds grand, but it's actually a common symptom encountered in daily life.

After exercise or a half-bath, the skin suddenly reddens, small hives appear, and it becomes itchy and prickly. In severe cases, it can become so intense that breathing feels restricted. On the surface, it's easy to assume "there's a lot of heat." This often leads to a reflexive response of "I should use cold medicine." However, Traditional Korean Medicine (TKM) delves a step deeper here.

Heat (熱) is Not Simple

In TKM, 'heat' doesn't simply refer to a high body temperature. 'Heat' is the result of a disrupted harmony in the body's internal energy flow, specifically the circulation of Qi and Blood (氣血運行, *qi-xue yun-xing*).

To put it more simply: Heat is not a matter of quantity, but of flow and distribution. Keeping this in mind when examining cholinergic urticaria allows us to finally understand its various pathological states.

Revisiting 'Heat' in the Classics

1. Zhu Zhenheng (朱震亨) — *Dongyuan Shishu* (東垣十書), "On Internal Injury and Fever" (內傷發熱論)

Zhu Zhenheng stated:

「If the Spleen and Stomach are damaged, Qi and Blood become deficient, Yin Fire moves internally, and feverish illness occurs.」(脾胃一傷，氣血虧損，陰火內動，發為熱病。)

What does this mean? It means that when the body's Qi and Blood (*qi-xue*) become deficient, Yin (陰) becomes insufficient, naturally leading to internal heat (*nei-re*), or a hot sensation inside.

Among patients with cholinergic urticaria, many have "deficient heat (虛熱, *xu-re*)" arising from repeated overwork, bleeding, or a constitutional deficiency of Yin Blood (陰血不足, *yin-xue bu-zu*). In this type, the face appears red and the skin is itchy externally, but internally, Yin fluid (*yin-ye*) is depleted, and the sweating mechanism (腠理開闔, *cou-li kai-he*) does not function properly.

In other words, it follows a pathological chain of vacuity/deficiency (虛損, *xu-sun*) → deficient heat (虛熱, *xu-re*) → anhidrosis (無汗, *wu-han*) → skin problems.

2. Zhang Jiebin (張介賓) — *Jingyue Quanshu* (景岳全書), "The Six Depressions" (六鬱)

Zhang Jiebin explains heat thus:

「Whenever Qi is stagnant, heat is generated.」(凡氣鬱則生熱。)

「The six depressions (*liu-yu*) refer to the stagnation of Qi, Blood, Dampness, Food, Phlegm, and Fire.」(六鬱者，氣、血、濕、食、痰、火之鬱也。)

What's important here is "鬱" (*yu*), or stagnation. That is, a blockage. The problem isn't that there's a lot of heat, but that heat cannot dissipate and remains trapped inside.

Another type of cholinergic urticaria. When exercising or exposed to heat, the heat should circulate to the surface and naturally dissipate through sweating (*fa-han*), but the pathway is blocked. The exterior Qi (氣表, *qi-biao*) is obstructed, the pores (毛竅, *mao-qiao*) do not open, and the heat stagnates internally, erupting as hives.

→ Stagnant Heat Type Cholinergic Urticaria.

3. Wang Qingren (王淸任) — *Yilin Gaicuo* (醫林改錯)

Wang Qingren spoke of Blood Stasis (瘀血, *yu-xue*) thus:

「If Blood Stasis remains stagnant, it will invariably generate heat.」(瘀血留滯，必致生熱。)

「If Blood does not circulate, heat will become stagnant.」(血不行則熱鬱。)

Some cases of cholinergic urticaria are not merely problems with the flow of Qi and Blood, but rather "localized blood flow obstruction"—where micro-circulation is blocked, causing heat to accumulate densely, which then manifests as skin reactions (itching, redness, swelling). This pattern is often observed in patients with hypertension and sensitive vascular reactivity.

In Summary

Even for a single condition like cholinergic urticaria, 'heat' presents with such diverse characteristics.

To Treat Heat is to Treat the Person

The classics of Traditional Korean Medicine consistently state: The problem is not the heat itself, but the breakdown of the body's system for managing heat. Cholinergic urticaria is no different. Don't simply try to extinguish heat just because it feels hot. Sometimes, Yin needs to be supplemented; at other times, Qi needs to be circulated; and sometimes, Blood needs to be released from stagnation. Don't just look at what's visible on the surface; you must read the underlying flow. That is the profound perspective of Traditional Korean Medicine.

Virtual Example

Here's an example of a patient. (※ Please note that this is a hypothetical case for illustrative purposes, not an actual patient.)

Ms. Kim, 36, a yoga instructor. For body shape management and health, she regularly combined 2-3 hours of high-intensity yoga with half-baths daily. Due to her high exercise volume, her physique is quite lean, her menstrual flow is scanty, and her lips tend to chap easily when tired.

In recent months, after half-baths or yoga, just as she was about to sweat a little, her body would flush red, become itchy, and small, hive-like rashes would appear. Areas like her neck, upper chest, and inner arms were particularly sensitive, and in severe cases, it was accompanied by a mild feverish sensation and palpitations.

At first, she dismissed it as "just from intense exercise," but the symptoms gradually worsened and began to affect her daily life. In this case, should we simply view it as "post-exercise heat" and only prescribe heat-clearing medicine (*qing-re yao*)? No.

Upon closer examination, Ms. Kim simultaneously presents with clues such as excessive sweating habits, Yin-Blood depletion (陰血消耗, *yin-xue xiao-hao*) (scanty menstrual flow, dryness), and a slight tendency towards anhidrosis (無汗症傾向, *wu-han zheng qing-xiang*) (feeling like she doesn't sweat easily).

Therefore, her cholinergic urticaria exhibits a complex pattern, intertwining "deficient heat (虛熱, *xu-re*)" due to "Yin-Blood deficiency (陰血虧損, *yin-xue kui-sun*)" and "stagnant heat (火鬱, *huo-yu*)" due to "obstruction of exterior Qi circulation (氣鬱表鬱, *qi-yu biao-yu*)."

What if we indiscriminately suppress this with cold heat-clearing medicine? The superficial heat sensation might subside temporarily, but the fundamental Yin-Blood deficiency would worsen, potentially exacerbating the urticarial reaction.

Instead, this case requires an approach in three directions: generating fluids and nourishing Yin (生津滋陰, *sheng-jin zi-yin*), tonifying Blood and nourishing Yin (補血補陰, *bu-xue bu-yin*), and dispersing and promoting circulation (宣發疏通, *xuan-fa shu-tong*).

Having heat does not automatically mean clearing heat. Feeling hot does not automatically mean cold medicine. Traditional Korean Medicine always asks:

"Where does this heat come from?"

"Why is the heat unable to circulate?"

"What are this person's fundamental constitution and current condition?"

Only when these questions are not overlooked can one accurately discern the pathology hidden behind the superficial phenomenon of heat.