Why Does Pus Come Out When I Squeeze My Armpit?

Symptoms of cysts or abscesses in the armpit may include: 

• Swelling under the skin
• Pain and tenderness in the armpit
• Warmth and redness in the armpit
• A visible build-up of white or yellow pus under the skin in the armpit
• Fever 
• Chills

The main symptom of hidradenitis suppurativa include is painful, swollen, red bumps that may drain pus or blood. 

• The bumps may:
  • Become infected
  • Have a foul odor
  • Last a long time and worsen over time
• Skin may harden and form scars around the bumps
• Several bumps may form in one area and cause a small “tunnel” in the skin called a sinus tract
• In addition to the armpits, common locations for the bumps are places where skin rubs together, including:
  • Groin
  • Inner thighs
  • Buttocks
  • Around or near the anus
  • Under the breasts

The cause of a pus coming from the armpit is diagnosed with a patient history and physical examination of the area. Depending on the suspected cause of the pus in the armpit, tests may include: 

• Blood tests
• Complete blood cell count with differential and platelet counts (occasionally elevated white blood count)
• Erythrocyte sedimentation rate (ESR)
• C-reactive protein assay
• Urinalysis
• Serum multiphasic analysis with determination of the serum iron level and serum protein electrophoresis 
• Bacteriologic analysis, usually with a culture swab
• Immunochemistry for various cytokeratins and 6 desmosomal cadherins
• Histologic examination
• Ultrasound of hair follicles and skin thickness may help reveal abnormalities deep within the follicle.
• Fluid culture from the lump to check for infection
• Tissue biopsy

Three criteria need to be met for a diagnosis of hidradenitis suppurativa, including:

1.) The lesions are typical:

• They are painful, red, and papules smaller than 1 cm in diameter or nodules larger than 1 cm in diameter
• Abscesses are painful and tender, and there is discharge from the papules or nodules
• Scarring (dermal contracture)
• Double-ended acne papules (comedones)

2.) Lesions have a characteristic distribution

3.) Lesions are recurrent (at least two recurrences over a period of six months)

Treatment for a lump in the armpit depends on the cause. Often, lumps are benign and don’t need treatment. 

Treatment for a cyst or abscess the armpit that is infected may include: 

• Warm compresses
• Antibiotics if infected
• Draining or lancing the cyst or abscess

In the early stages, treatment for hidradenitis suppurativa may include conservative measures and lifestyle modifications, such as:

• Shower daily and gently wash areas of HS with hands 
• Weight loss if overweight or obese
• Don’t smoke
• Use ordinary soaps and antiseptic and antiperspirant agents (e.g., 6.25% aluminum chloride hexahydrate in absolute ethanol)
• Apply warm compresses with sodium chloride solution or Burow’s solution
• Wear loose-fitting clothing on areas where HS is present 
• Laser hair removal

Medications that are used to treat hidradenitis suppurativa include:

• Antibiotics
• Retinoids
• Corticosteroids 
• Antiandrogens
• Immunosuppressants 
• Estrogen derivatives 
• 5-Alpha-reductase inhibitors 

Surgery may be indicated once abscesses, fistulas, scars, and sinus tracts have formed. Non-ablative radiofrequency therapy may be used for patients in certain stages of the disease.