Pruritus is a skin condition characterized solely by itching without any primary skin lesions. Clinically, it is generally classified into two types: localized and generalized. Localized pruritus is most commonly found in areas such as the anus, vulva, and scrotum, while generalized pruritus affects a broader area of the body. This condition is similar to what Traditional Chinese Medicine refers to as “yangfeng” (itching wind).
I. Causes
Modern medicine holds that generalized pruritus may be caused by certain internal diseases, such as diabetes, uremia, liver disease, thyroid dysfunction, blood disorders, lymphosarcoma, Hodgkin’s disease, mycosis fungoides, parasitic diseases, focal infections, drug reactions, alcohol consumption, and the consumption of spicy or irritating foods. In addition, dry, cold, or hot weather, excessive bathing, and the use of overly alkaline soaps can also trigger this condition. Localized pruritus is often caused by local friction, irritation from secretions, hemorrhoids, vaginal discharge, trichomoniasis, fungal infections, or pinworms.
Traditional Chinese Medicine holds that the onset of this condition can be attributed to a variety of factors. When pathogenic factors such as wind-cold or wind-heat invade the skin’s surface and cannot be properly dispersed, itching occurs; or when damp-heat accumulates and cannot be released, remaining in the skin, itching also results; or when blood deficiency combined with liver hyperactivity leads to the generation of wind and dryness, causing the skin to become malnourished, resulting in unrelenting itching. Furthermore, emotional distress and irregular dietary habits can also trigger or exacerbate this condition.
II. Clinical Manifestations
Generalized pruritus: Itching is often paroxysmal, particularly severe at night, and is frequently triggered or exacerbated by emotional fluctuations, changes in weather, alcohol consumption, or the ingestion of spicy or irritating foods. The severity of itching varies from person to person, ranging from mild to intense and unbearable. Due to repeated scratching, the skin often develops secondary lesions such as scratch marks, scabs, hyperpigmentation, eczematous changes, or lichenification. Some patients may also experience systemic symptoms such as dizziness, insomnia, loss of appetite, and lethargy.
Localized Pruritus: Itching is confined to a specific area, such as anal pruritus, scrotal pruritus, or vulvar pruritus. Due to prolonged scratching, the affected skin may become thickened, develop lichenification, fissures, or eczematous changes.
III. Diagnosis
Given that the condition presents only with itching and no primary skin lesions, combined with the location of onset, age, season, and triggering factors, diagnosis is generally straightforward. However, it must be differentiated from conditions such as eczema, neurodermatitis, and scabies.
IV. Treatment
Modern Medical Treatment
(1) Systemic Treatment: Antihistamines such as chlorpheniramine, diphenhydramine, or promethazine may be used, or intravenous injections of calcium supplements or sodium thiosulfate may be administered. For severe symptoms, corticosteroids may be used for a short period. For senile pruritus, sex hormones may be used appropriately; for example, ethinyl estradiol for women and testosterone propionate for men.
(2) Topical Treatment: Topical agents such as calamine lotion, anti-itch solutions, and corticosteroid ointments or creams may be used. For localized pruritus, appropriate topical medications may be selected.
Traditional Chinese Medicine Differential Diagnosis and Treatment
(1) Wind-Heat Pattern: Manifested as skin itching that worsens with heat and improves with cold, accompanied by dry mouth and restlessness. The tongue is red with a thin yellow coating, and the pulse is floating and rapid. Treatment should focus on dispelling wind, clearing heat, cooling the blood, and relieving itching; the Xiao Feng San formula with appropriate modifications may be used.
(2) Wind-Cold Pattern: Manifested as skin itching that worsens with cold and improves with warmth, accompanied by aversion to cold and absence of sweating; the tongue is pale with a thin white coating, and the pulse is floating and tight. Treatment should focus on dispelling wind and dispersing cold, as well as harmonizing the ying and wei qi; Gui Zhi Tang with appropriate modifications may be used.
(3) Damp-Heat Pattern: Manifests as skin itching that oozes fluid when scratched, accompanied by a bitter taste in the mouth, dry mouth, and yellow urine; the tongue is red with a thick, yellow coating, and the pulse is slippery and rapid. Treatment should focus on clearing heat, draining dampness, dispelling wind, and relieving itching; Longdan Xiegan Decoction with appropriate modifications may be used.
(4) Blood-Deficiency with Wind-Dryness Pattern: Manifested by dry, flaky, and itchy skin, accompanied by dizziness, insomnia, and palpitations; pale tongue with a thin white coating; and a fine, weak pulse. Treatment should focus on nourishing the blood, moistening dryness, dispelling wind, and relieving itching; Siwu Xiaofeng Decoction with appropriate modifications may be used.
Acupuncture Therapy: Select acupoints such as Quchi (LI11), Hegu (LI4), Xuehai (SP10), Zusanli (ST36), and Sanyinjiao (SP6) for needling. For auricular acupuncture, select points such as Shenmen (HT7), Subcortical (AC1), and Endocrine (AC10).
V. Prevention
Avoid excessive scratching, rubbing, and washing with hot water.
Avoid using soaps that are too alkaline.
Refrain from drinking alcohol and consuming spicy or irritating foods.
Actively treat the underlying disease.
Maintain a positive state of mind and avoid emotional fluctuations.