A person with axillary lymphadenitis has inflammation of the lymph nodes in the armpit, usually caused by a bacterial infection. The infection causes the lymph glands in the armpit become swollen and tender.

Swelling in the armpit may be caused by:

• Lymphadenitis
• Mastitis
• Skin cyst
• Skin abscess
• Viral infection
• Hidradenitis suppurativa
• Cancer:
• Lymphoma
• Leukemia
• Breast cancer