Why is the middle of a baby's lower lip turning blue or purple, and what should be done?

Generally, a bluish or purplish discoloration in the middle of an infant's lower lip may be caused by factors such as pigmentation, emotional excitement, local trauma, congenital laryngeal stridor, pneumonia, and so on. It is recommended to seek timely medical attention and follow the doctor's guidance for treatment, which may include general care, medication, and other approaches. Detailed explanations are as follows:

1. Pigmentation

In some infants, increased localized pigmentation of the lower lip due to hereditary factors may cause a purplish appearance. This typically does not affect the infant's health. The main precaution is to avoid injuries or irritation to the lips to prevent further darkening of the pigmentation.

2. Emotional Excitement

When infants cry intensely or become emotionally excited, they may hyperventilate, leading to respiratory alkalosis, which can cause peripheral vasoconstriction and result in a purplish appearance in the middle of the lower lip. Parents should try to prevent prolonged episodes of intense crying, promptly comfort the infant, and meet their needs, such as timely feeding when hungry and changing wet diapers promptly.

3. Local Trauma

If the infant's lower lip sustains trauma such as bumps or pressure, tissue damage and ruptured blood vessels may lead to bruising and a purplish appearance. This may also be accompanied by local swelling and pain. Cold compresses can be applied locally within the first 24 hours to reduce swelling and pain, followed by warm compresses after 24 hours to promote absorption of the bruising. Medication is generally not required.

4. Congenital Laryngeal Stridor

Congenital laryngeal stridor occurs due to underdevelopment of the laryngeal cartilage during fetal development. During inhalation, the laryngeal cartilage collapses, causing airway narrowing and impaired gas exchange, leading to oxygen deficiency and a bluish or purplish lip discoloration. It may also be accompanied by inspiratory stridor and breathing difficulties. Patients may follow their doctor's instructions to use medications such as vitamin D drops, pediatric calcium carbonate D3 granules, calcium acetate granules, etc.

5. Pneumonia

Pneumonia is mainly caused by infections from pathogens such as bacteria or viruses. Inflammation in the lungs impairs gas exchange, leading to insufficient oxygen intake and impaired carbon dioxide elimination, which may cause lip discoloration. It may also be accompanied by symptoms such as fever and cough. Treatment may involve medications such as amoxicillin clavulanate potassium for oral suspension, cefixime granules, ribavirin granules, etc., under the guidance of a physician.

In daily life, it is important to ensure the safety of the infant's environment to prevent injuries and maintain good indoor air circulation to prevent carbon monoxide poisoning.