Lower leg erythrocyanosis

　　1. Etiology

　　This disease is more common in cold areas, and it is considered to be a vascular abnormal reaction caused by long-term cold. It often occurs in areas with thick subcutaneous fat layers. Some scholars also believe it is related to tuberculosis, endocrine dysfunction, and congenital vascular dysfunction.

　　2. Pathogenesis

　　The pathogenesis is not yet fully understood. Some scholars believe it is a vascular abnormal reaction caused by cold in areas with thick subcutaneous fat layers.

　　Since this disease is more common in cold areas, it is considered to be a vascular abnormal reaction caused by long-term cold. It often occurs in areas with thick subcutaneous fat layers. Some scholars also believe it is related to tuberculosis, endocrine dysfunction, and congenital vascular dysfunction. Therefore, vascular constriction can cause ischemia of the local skin and subcutaneous tissue, resulting in limb pain, and accompanied by venous return obstruction, which may lead to varicose veins of the lower limbs. Severe varicosities can cause skin ulceration and hyperpigmentation.

　　Commonly seen in young women, it often occurs on the lower third of the lower leg and the thigh, with the ankle area of the lower leg being particularly common. The affected skin shows dark red or deep purple-red edematous patches. Unilateral onset is rare, and the local skin temperature is lower. It can also manifest as follicular erythema, follicular keratosis, or diffuse desquamation. A few nodules can ulcerate to form small ulcers. Some cases may also have a history of nocturnal leg cramps, and may be accompanied by chilblains, erythrocyanotic nodules, with mild自觉 symptoms, occasionally feeling itchy and stuffy. The course of the disease is variable, with some improving naturally over several years, while others may develop slowly with skin thickening and fibrosis, exacerbating in winter.

　　Since this disease is more common in cold areas, it is considered to be a vascular abnormal response caused by long-term cold. It often occurs in areas with thick subcutaneous fat layers. Therefore, the prevention of this disease mainly focuses on the etiology, emphasizing the need to keep warm, such as wearing long pants, woolen socks, cotton shoes, or leather shoes to resist the cold; wearing elastic stockings can keep warm and also has the effect of controlling edema; strengthen physical exercise and cold resistance training; reduce weight.

　　Histopathology:Mild cases may only have a few acute inflammatory cells or a few lymphocytes in the dermis; severe cases may have vascular dilatation in the dermis, swelling of vascular endothelial cells, edema in the dermis, and a few red blood cells may leak out, and thrombosis may occasionally occur, causing infarction.

　　1. Pay attention to diet:Eat more warm and spicy foods appropriately, such as beef, pork, mutton, rabbit meat, chicken, bok choy, chives, ginger, lotus root, tomatoes, potatoes, chestnuts, walnuts, peanuts, etc., and avoid eating cold and cool foods to prevent exacerbation or recurrence.

　　2. Pay attention to daily life:Avoid catching a cold, pay attention to wearing warm clothing, strengthen physical exercise and cold resistance training, and reduce weight.

　　I. Treatment

　　1. General treatment:Pay attention to keeping warm and avoiding the cold, such as wearing long pants, woolen socks, cotton shoes, or leather shoes to resist the cold; wearing elastic stockings can keep warm and also has the effect of controlling edema; strengthen physical exercise and cold resistance training; reduce weight.

　　2. Drug treatment:Oral Danshen tablets 0.4mg, 3 times a day, can improve blood circulation. Traditional Chinese medicine Si Ni Decoction or Danggui Si Ni Decoction is effective for the treatment of this disease. This disease does not require treatment with corticosteroid hormones.

　　II. Prognosis

　　The course of the disease is unpredictable, with some experiencing natural improvement over several years, while others develop slowly with skin thickening and fibrosis. It worsens in winter.