bubble_chart Overview

Neonatal scleredema (neonatal scleredema) is a syndrome caused by cold injury, infection, or premature labor, with cold injury being the most common cause, known as the cold injury syndrome. It is characterized by subcutaneous fat hardening and edema.

bubble_chart Pathogenesis

The body surface area of newborns is relatively large, with thin and delicate skin and abundant blood vessels, making them prone to heat loss. Brown fat is a unique tissue in newborns, and its metabolism serves as the primary energy source when the newborn urgently needs to generate heat in a cold environment, while white fat provides energy during hunger. If the surrounding environmental temperature is too low and excessive heat is lost, brown fat can be easily depleted, leading to a drop in body temperature. Severe infections in newborns can also prevent a rise in body temperature. In these situations, subcutaneous fat is prone to solidify and harden. Additionally, low temperatures cause peripheral capillaries to dilate and permeability to increase, making edema more likely to occur, ultimately resulting in sclerema.

Research on the effects of low body temperature on the human body is ongoing. ① During hypothermia, peripheral circulatory resistance decreases, leading to blood stasis and tissue hypoxia. Meanwhile, central heart blood circulation decreases, heart rate slows, and urine output reduces. During rewarming, blood circulation increases, and if urine output does not correspondingly rise, it may lead to heart failure or even pulmonary edema and hemorrhage. ② During hypothermia, breathing slows or may even pause, increasing the risk of respiratory acidosis. Additionally, inadequate nutrient intake can cause metabolic acidosis, resulting in more severe acidosis in severe cases of sclerema neonatorum. ③ During hypothermia, glucose metabolism is impaired. Initially, hyperglycemia may occur, but due to increased glucose consumption, hypoglycemia may follow. ④ During hypothermia, hematocrit and blood viscosity increase, while platelet count and heparin-like substances decrease. These factors can collectively lead to coagulation disorders, triggering disseminated intravascular coagulation (DIC). Severe infections, compounded by shock, further increase the risk of DIC.

bubble_chart Clinical Manifestations

This condition mostly occurs within 7 to 10 days after birth, with body temperature not rising, remaining below 35°C, and in severe cases below 30°C. The core temperature (rectal temperature) may be lower than the surface temperature (axillary temperature). The skin and subcutaneous tissues develop hardening and swelling, appearing light red or dark red. In cases of severe circulatory insufficiency, the skin may appear pale gray or cyanotic. The hardening and swelling first appear in the lower limbs, buttocks, cheeks, and lower abdomen, then spread to the upper limbs and the entire body. Sometimes, the condition presents as hardening without swelling, with the skin appearing pale, resembling rubber, and localized, affecting only the thighs and buttocks. This scenario often occurs in leredema neonatorum caused by infectious diseases. Severe leredema neonatorum can lead to shock, pulmonary hemorrhage, and DIC.

The severity grading is based on the criteria discussed at the 1989 National Neonatology Group Meeting, as shown in Table 1.

Table 1 Severity Grading of Neonatal Leredema Neonatorum

Grade I	Extent of hardening and swelling *	Temperature	Rectal-axillary temperature difference	Organ function changes
Mild	<20%	>35°C	Positive value	None or Grade I functional impairment
Moderate	20–50%	<35°C	0 or positive value	Significant functional impairment
Severe	>50%	<30°C	Negative value	Organ failure, DIC, pulmonary hemorrhage

* Estimation of body surface area percentages: head and neck 20%, upper limbs 18%, chest and abdomen 14%, back and lumbosacral region 14%, buttocks 8%, lower limbs 26%.

bubble_chart Auxiliary Examination

(1) Blood Routine Test There is no significant change in the total white blood cell count in peripheral blood. In cases of concurrent infection, the total white blood cell count and neutrophils may increase or decrease to varying degrees. A marked increase or decrease in neutrophils suggests a poor prognosis.

(2) DIC Screening Test For critically ill neonates with suspected DIC, the following six tests should be performed:

① Platelet Count: Often shows progressive decline, with approximately 2/3 of patients having a platelet count <100×10⁹/L (100,000/mm³).

② Prothrombin Time: Prolonged in severe cases, ≥20s for neonates within 4 days of birth, and ≥15s for those aged 5 days or older.

③ Kaolin Partial Thromboplastin Time: >45s.

④ Plasma Thrombin Time: Normal range for neonates is 19–44s (16.3s for older children), and a value >3s compared to the same-age control group is diagnostically significant.

⑤ Fibrinogen: <1.17g/L (117mg/dl), with <1.16g/L (160mg/dl) being of reference value.

⑥ 3P Test (Plasma Protamine Paracoagulation Test): 65% of normal neonates show enhanced fibrinolysis on the first day of life, and fibrin degradation products (FDP) may be present, so the 3P test can be positive. A positive result after 24h is abnormal, but in advanced DIC, the 3P test may turn negative.

(3) Blood Gas Analysis Due to hypoxia and acidosis, blood pH decreases. PaO₂ decreases, while PaCO₂ increases.

(4) Blood glucose is often decreased, and creatinine or non-protein nitrogen may be elevated.

(5) Ultra-Micro Red Blood Cell Electrophoresis Time Measurement Due to increased blood viscosity, red blood cell electrophoresis time is prolonged.

(6) Electrocardiogram Changes Some cases may show ECG changes, such as prolonged Q-T interval, hypotension, flattened T waves, or S-T segment depression.

bubble_chart Diagnosis

1. Clinical Manifestations This disease often occurs in cold seasons and is commonly seen in newborns shortly after birth or within the first week of life. There is often a history of low environmental temperature and inadequate warmth. Cases caused by factors such as premature labor or infection may also occur in summer. The infant's body temperature drops to 31–35°C or even around 26°C, which can be measured using a domestically produced low-temperature thermometer (30–40°C). The infant exhibits weak crying or no crying, inability to suck, and reduced spontaneous limb movements. The skin initially appears deep red and later turns dark red; in severe cases, it becomes pale or cyanotic. The limbs and trunk are cold to the touch, and the pulse is weak and difficult to palpate. The skin and subcutaneous tissues first develop edema, which later hardens, resembling hard rubber in severe cases. Sclerema initially affects the calves, cheeks, and shoulders, then spreads to the outer thighs, buttocks, and upper limbs, and may eventually involve the entire body. Respiratory distress may occur due to hardening of the chest and abdomen, and the inability to open the mouth due to hardened cheeks. The infant may exhibit dull heart sounds, bradycardia, low responsiveness, oliguria or anuria, and later, bloody discharge from the nose and mouth, leading to pulmonary hemorrhage and death.

2. Laboratory Tests (Refer to the above description)

3. Diagnosis and Severity Grading of Neonatal Sclerema There is currently no unified consensus (see Table 1).

Some classify the condition into mild, moderate, and severe grades based on the extent of sclerema, general condition, body temperature, and the presence of shock or pulmonary hemorrhage.

4. Diagnosis of Skin Sclerema Extent The extent of skin sclerema is classified into mild, moderate, and severe grades: - Grade I: Sclerema involves less than 30% of the body surface. - Grade II: Sclerema involves 30–50% of the body surface. - Grade III: Sclerema involves more than 50% of the body surface.

5. Diagnosis and Grading of Subcutaneous Fat Firmness in Neonatal Sclerema - Grade I: Subcutaneous fat is slightly firm, and the skin is mildly red. - Grade II: Edema is more pronounced, subcutaneous fat elasticity is largely lost, and the skin is slightly dark red. - Grade III: Edema is significant, subcutaneous fat elasticity is completely lost (resembling hard rubber), and the skin is dark red.

6. Diagnostic Criteria for Severe Neonatal Sclerema Based on the "Trial Protocol for Critical Case Scoring Method" formulated by the Office of the Children's Emergency Program under the Ministry of Health's Department of Maternal and Child Health, the following two indicators are used:

(1) Rectal temperature below 30°C with Grade II or higher sclerema, regardless of extent.

(2) Rectal temperature below 33°C with Grade II or higher sclerema involving more than 60% of the body surface.

Meeting either of the above criteria qualifies for a diagnosis of severe neonatal sclerema.

bubble_chart Treatment Measures

1. Rewarming is the primary measure for treatment. (1) For mild cases, after a warm water bath, wrap the child in pre-warmed cotton blankets and place them in a warm room at 24–26°C, supplemented with a hot water bottle. Gradually increase the water temperature from 40°C to 60°C, and the body temperature can rise to normal relatively quickly. (2) For grade II and grade III cases, first place the child on a far-infrared open warming bed, adjusting the temperature to 1.5–2°C above the child’s body temperature. This can raise the body temperature by approximately 1°C every 30 minutes. As the child’s temperature rises, continue to increase the warming bed’s temperature. When the body temperature reaches 34°C, the child can be moved to a closed incubator, maintaining the incubator temperature at around 35°C. To reduce radiant heat loss, cover the area slightly away from the child’s body with a transparent plastic sheet, leaving the head and face exposed, and place a small hat on the head for warmth. (3) In addition to the above methods, rewarming can also be achieved through warm water baths, warm saline enemas, or other methods. (4) If intravenous fluids or high-nutrient solutions are being administered, wrap the bottle with a hot towel to ensure the infused liquid enters the body at a certain temperature. (5) The supplied oxygen should also be preheated.

2. Nutrition and fluids: Ensure sufficient caloric and fluid intake. Initially, the caloric intake should at least meet basal metabolic needs, gradually increasing to normal requirements. The fluid volume is generally controlled at 60–80 ml/kg/day, administered slowly at a rate of about 4 ml/kg/h. Since cardiac and renal functions are reduced during hypothermia, the infusion volume should not be excessive. For hypoglycemic children, appropriately increase the glucose intake.

3. Medications

(1) For those with poor cardiac and renal function, cardiovascular active drugs such as dopamine and dobutamine can be administered. Dopamine should be given at a low dose of 2–5 μg/kg/min intravenously, as low doses can dilate renal and cerebral blood vessels, increasing urine output. Dobutamine enhances myocardial contraction without increasing heart rate, administered at 2.5–5 μg/kg/min intravenously, and can be used in combination with dopamine. Other drugs such as 654-2 can also be used, with an intravenous dose of 0.1–0.2 mg/kg every 15 minutes for about 3–4 doses. If complexion and heart rate improve, maintain with 1–2 mg/day intravenously and continue treatment for one week.

(2) The use of antibiotics is particularly important for neonatal leredema caused by infectious diseases. Drugs with high renal perianal abscess potential should be used sparingly. Although respiratory infections may occur in cold injury syndrome, broad-spectrum antibiotics should not be used prophylactically.

(3) Heparin therapy: The first dose is 1.5 mg/kg intravenously, followed by 0.5–1.0 mg/kg every 6 hours intravenously. Once prothrombin time and clotting time normalize, gradually reduce the frequency of administration. The treatment course is 7 days.

(4) Chinese medicinals: Focus on warming yang to dispel cold and invigorating blood to resolve stasis. Intravenous infusions of Salvia, Carthamus, or Aconite Lateral Root injections can be used, or Sichuan Lovage Rhizome and Carthamus injections, or the compound formula Taohong injection, administered slowly twice daily.

bubble_chart Prognosis

In some regions, leredema neonatorum remains one of the important causes of neonatal death. For infants with a body temperature below 30°C, a sclerema area exceeding 50%, those born from premature labor, or severe infections leading to this condition, the seasonal disease mortality rate is high. Pulmonary hemorrhage is often the cause of death.

bubble_chart Prevention

Prevention is better than cure. ① Strengthen perinatal healthcare and prenatal examinations to reduce the occurrence of premature infants. ② Equip delivery rooms with heating facilities in cold seasons and regions. ③ Immediately after birth, wrap the newborn in pre-warmed towels and move them to a heated bed for care. ④ Monitor the body temperature of high-risk infants closely. ⑤ Provide early and active treatment for neonatal infectious diseases to prevent the onset of scleredema neonatorum.