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General Surgery · CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)

Hidradenitis

*Hidradenitis*

Hidradenitis is a specific purulent inflammation that develops in the apocrine sweat glands. The condition requires careful differential diagnosis, as it can clinically mimic other pyinflammatory processes of the skin and subcutaneous tissue.

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LocalizationOnly apocrine sweat glands are affected
DifferenceThe infiltrate lacks a necrotic core, unlike a furuncle
ImmunizationStaphylococcal toxoid is used in therapy
Radical treatmentIf there is a risk of sepsis, all adipose tissue in the affected area is excised
2 min readFor medical studentsUpdated Sep 20, 2026
Material prepared by WhiteCoat Pro editorial team based on platform study guidesReviewed by medical editor: Aulov A. A., general practitioner · 09/24/2026

Differential diagnosis

Making an accurate diagnosis requires ruling out other conditions with a similar clinical presentation. First and foremost, hidradenitis must be differentiated from two pathologies:

  • Furuncle. The main difference lies in the structure of the inflammatory lesion. In hidradenitis, the infiltrate protruding above the skin never has a follicular pustule. Furthermore, this condition completely lacks a necrotic center (purulent core), which is the hallmark of a furuncle.
  • Axillary lymphadenitis. Unlike sweat gland inflammation, lymphadenitis is characterized by a deeper infiltrate. The tumor-like mass in lymph node involvement is not tethered to the skin, while the lymph nodes themselves are significantly enlarged.

Possible complications

Purulent inflammation of the apocrine glands tends to spread to surrounding tissues. In unfavorable cases or without timely treatment, the following complications may develop:

  1. Phlegmon. Occurs when the pyinflammatory process extends beyond the gland and involves the surrounding subcutaneous adipose tissue in the pathological process.
  2. Lymphadenitis. Develops secondarily when the infection spreads through lymphatic pathways and affects regional lymph nodes.
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Conservative therapy

At the infiltration stage, prior to the formation of a purulent cavity, comprehensive non-surgical treatment is used.

Medical support:

  • Systemic antibiotic administration.
  • Prescription of long-acting sulfonamides.
  • Specific immunization of the body using staphylococcal toxoid.

Local treatment (in the axillary region):

  • Careful shaving of hair in the affected area.
  • Antiseptic treatment of the skin with alcohol.
  • Applying 3% brilliant green solution to the inflamed area.

Physiotherapeutic procedures: Ultra-high frequency (UHF) therapy and ultraviolet (UV) irradiation of the inflammatory focus are indicated.

Surgical treatment

Surgical intervention becomes necessary when the disease progresses to the purulent-necrotic phase.

  • Main indication: abscess formation in hidradenitis.
  • Standard scope of surgery: surgical opening of the formed abscess and thorough removal of the purulent contents.
  • Severe course: if prolonged conservative treatment fails or there is a real threat of sepsis, the tactic is changed to a radical one. In such cases, a wide excision of all adipose tissue in the axilla is performed. In its scope and principles, this intervention is analogous to the surgery performed for a carbuncle.
How to memorize

To distinguish hidradenitis from a furuncle, remember: "No core — no follicle." Hidradenitis affects the apocrine gland (without a necrotic core), while a furuncle affects the hair follicle (with a core).

Class and exam questions

Can hidradenitis be confused with lymph node inflammation?

Yes, but in hidradenitis, the infiltrate is superficial and tightly tethered to the skin, whereas in lymphadenitis, the mass is deeper and the skin over it is mobile.

When is surgery necessary for hidradenitis?

Surgical intervention is indicated exclusively in the event of abscess formation, i.e., when a cavity with pus has formed in the lesion.

What does local treatment involve prior to surgery?

It includes shaving hair in the affected area, treating the skin with alcohol and brilliant green solution, as well as physiotherapy (UHF, UV irradiation).

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What else to study on this topic

  • Anatomical features of apocrine and eccrine sweat glands
  • Mechanism of action of staphylococcal toxoid in purulent infections
  • Technique of radical excision of subcutaneous tissue in severe hidradenitis
  • Principles of using sulfonamides and antibiotics in purulent surgery

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Other topics from the section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"

Surgical infectionPathogens of surgical infectionPathogenesis of surgical infectionEndogenous intoxication in surgeryTreatment of surgical infectionFolliculitisAbscessErysipelasNecrotizing fasciitisCellulitisParaproctitisParotitisMastitisLymphangitisLymphadenitisSuppurative bursitisPanaritiumOsteomyelitisAtypical forms of osteomyelitisSuppurative arthritisPeritonitisPurulent pleurisySepsisSurgical Infection: General Concepts and Pathogenesis
The entire section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"

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