What causes lumps under the armpit accompanied by swelling, pain, and a white, foul-smelling discharge?

Under normal circumstances, lumps in the armpit accompanied by swelling, pain, and white, foul-smelling discharge may be related to factors such as abscesses, folliculitis, furuncles (boils), sebaceous cysts, or acute lymphadenitis. Patients are advised to follow medical guidance for symptomatic treatment. Specific analyses are as follows:

1. Abscess

An abscess is a localized purulent inflammation caused by bacterial infection, typically accompanied by symptoms such as pain, swelling, and redness, with possible presence of white pus inside. Treatment under medical supervision may include oral medications such as amoxicillin capsules or cefuroxime axetil tablets.

2. Folliculitis

Frequent use of low-quality bathing products or loofahs may damage hair follicles, making them susceptible to bacterial infection and resulting in inflammatory symptoms such as red papules and pain. Topical medications such as mupirocin ointment or fusidic acid cream can be applied as directed by a physician.

3. Furuncle (Boil)

A furuncle is a localized purulent inflammation caused by bacterial infection around a hair follicle, usually presenting with pain, swelling, and redness, and may contain white pus. If the furuncle has developed pus, surgical incision and drainage under medical supervision may be required.

4. Sebaceous Cyst

Commonly occurs on the head, face, shoulders, and buttocks, but may also appear in the armpit. These cysts are mostly round, sometimes protruding from the skin surface, soft in texture, and movable. When ruptured, they release a white, paste-like substance composed of sebum, fragmented sebaceous gland cells, and abundant cholesterol crystals, often with a foul odor. Patients may take antibiotic medications such as cefuroxime axetil tablets or amoxicillin capsules under medical supervision.

5. Acute Lymphadenitis

This condition commonly affects lymph nodes in the head, neck, armpits, and groin, usually resulting from bacterial infections in the corresponding lymphatic drainage areas. Affected lymph nodes become significantly enlarged and tender; if an abscess has formed, there may be a fluctuant sensation, and in severe cases, rupture with pus discharge and foul smell. Under medical guidance, patients may take medications such as Pudilan oral liquid or Lanqin oral liquid.

In addition, these symptoms may also be associated with conditions such as urticaria or herpes. If patients experience discomfort, it is recommended to seek timely medical evaluation at a hospital to avoid delays in diagnosis and treatment.