There's a small hard bump on the eyebrow that has become pus-filled. What could be causing this, and what should I do?

There is a small hard lump on the eyebrow that discharges pus, which may be caused by folliculitis, acne, or sebaceous cysts. Treatment options such as medication or surgery can help improve the condition. Specific analyses are as follows:

1. Folliculitis

Folliculitis is usually a bacterial infection causing purulent inflammation, primarily due to Staphylococcus bacteria. If folliculitis occurs on the eyebrow, it may lead to symptoms such as pustules, red papules, and itching. Patients can use medications like ofloxacin gel, fusidic acid cream, or mupirocin ointment under medical guidance.

2. Acne

The eyebrow area is part of the facial skin and contains abundant sebaceous glands. Poor facial hygiene may lead to acne, resulting in papules, pustules, nodules, and other lesions. Patients may follow medical advice to use medications such as adapalene gel, erythromycin ointment, or kojic acid and vitamin A acid gel.

3. Sebaceous Cyst

If the opening of a sebaceous gland on the eyebrow becomes blocked, secretions may accumulate internally and form a sebaceous cyst, leading to the aforementioned symptoms. The usual treatment for sebaceous cysts is surgical removal of the cyst.

In addition, similar symptoms may also result from flat warts, common warts, urticaria, etc. It is important to seek timely medical evaluation and treatment at a hospital.