Acne vulgaris typically involves outer skin blemishes like pimples, while acne inversa affects deeper layers of the skin, leading to painful nodules.

Acne is a skin condition that can cause pimples, cysts, and other skin lesions.

Acne vulgaris and acne inversa may sound similar; however, they manifest with distinct symptoms and require different approaches to treatment.

Acne vulgaris typically presents with facial blemishes and responds to topical treatments. Acne inversa can affect the face but more often appears in the armpits, groin, buttocks, and breast areas, requiring more specialized care.

Acne vulgaris is the most common and typical form of acne. When people refer to “acne,” they’re usually talking about acne vulgaris.

Acne vulgaris is a chronic skin condition that can manifest as both inflammatory and noninflammatory lesions, including pimples, blackheads, whiteheads, and, in some cases, deeper cysts or nodules.

The condition happens because the glands in your skin that produce oil (sebaceous glands) become too sensitive to male hormones called androgens. This sensitivity, combined with the presence of a bacterium called Cutibacterium acnes, leads to inflammation and the development of acne.

Acne is most common among young people, affecting between 35% to over 90% of adolescents, but it can affect people of all ages. It primarily affects the face but can also appear on the upper arms, trunk, and back.

Acne vulgaris symptoms

Acne vulgaris is characterized by a variety of symptoms, which can range from mild to severe.

Common symptoms of acne vulgaris include:

  • comedones (blackheads and whiteheads)
  • papules (small, raised, red or pink bumps)
  • pustules (red bumps with white or yellow centers)
  • nodules (painful, solid lumps under the skin)
  • cysts (deep, pus-filled lumps)
  • inflammation (redness and swelling)
  • scarring
  • hyperpigmentation (dark spots)
  • oily skin (excess sebum production)
  • tenderness

Acne inversa (also called hidradenitis suppurativa) is a chronic inflammatory condition that mainly affects body areas with sweat glands, like the armpits and anus-genital region. It often begins with painful nodules, leading to tunnels (called fistulas) and tissue scarring.

This condition typically begins after puberty and is more common in people of African descent. Its prevalence varies, ranging from less than 1–4%, depending on the region.

Acne inversa symptoms

The symptoms of acne inversa include:

  • painful, inflammatory nodules in areas with sweat glands
  • sterile abscesses (painful, swollen areas filled with pus)
  • sinus tracts (channels) and fistulas (abnormal connections)
  • tissue fibrosis
  • hypertrophic scarring (raised, thickened scars)
  • bad-smelling discharge
  • appearance in regions with sweat glands, including the armpits, groins, anal fold, and sometimes skin folds in individuals with obesity

Both conditions share some similarities related to skin lesions, but they differ significantly in terms of locations, age of onset, severity, and treatment approaches.

Here are some key differences that can help in telling them apart.

Acne vulgaris:

  • is common on the face, chest, and back
  • presents with various lesion types
  • typically starts during adolescence
  • affects a wide age range
  • has lesions that may come and go
  • responds to common acne treatments

Acne inversa:

  • most commonly affects the armpits, groin, buttocks, and under breasts
  • is characterized by painful nodules and abscesses
  • typically starts after puberty (primarily affects adults)
  • leads to scarring and tunnels
  • requires rigorous treatment such as antibiotics, immunosuppressive medications, or surgery

Acne vulgaris

The primary cause of acne vulgaris is an overreaction of the sebaceous glands to typical levels of androgens, particularly during adolescence. This leads to an increased production of sebum (skin oil) and the formation of comedones (clogged hair follicles).

The presence of the bacterium Cutibacterium acnes and inflammation can worsen the condition.

Several factors can contribute to the development or worsening of acne vulgaris, including the following:

  • medication use (for example, lithium or steroids)
  • exposure to excess sunlight
  • use of oil-based cosmetics
  • hormonal imbalances
  • genetic factors
  • diet (especially high glycemic load and milk consumption)
  • psychological stress
  • insulin resistance

Acne inversa

Acne inversa often begins with the blockage or inflammation of hair follicles and apocrine (sweat) glands. This leads to the formation of painful nodules, abscesses, and eventually narrow tunnel-like passages under the skin.

Current research indicates that immune dysfunctions and inflammatory processes may play a role in this condition.

Factors contributing to acne inversa can include the following:

  • smoking
  • obesity
  • changes in the immune system
  • excessive production of antimicrobial proteins

Acne vulgaris treatments include:

  • Topical treatments: These are over-the-counter or prescription creams and gels containing ingredients like benzoyl peroxide, salicylic acid, and retinoids.
  • Oral antibiotics: These include prescription antibiotics like doxycycline and minocycline for moderate to severe cases.
  • Oral contraceptives: These are for people assigned female at birth who have hormonal acne.
  • Isotretinoin (Accutane): Accutane is a powerful oral medication for severe, persistent acne.
  • Light and laser therapies: These are used in some cases to reduce acne symptoms.
  • Chemical peels: These can help improve skin texture and appearance.

Acne inversa treatments include:

  • Antibiotics: For less severe cases, antibiotics such as clindamycin-rifampicin or rifampicin-moxifloxacin-metronidazole can be used to target biofilm formation.
  • Oral acitretin: This is used after surgery to prevent relapses and in some cases of severe acne inversa.
  • Dapsone: This provides relief in some individuals but has a high relapse rate.
  • TNF-alpha inhibitors: Medications like infliximab, adalimumab, and etanercept can be used for severe cases, although etanercept can worsen the condition in rare cases.
  • Monoclonal antibody: This include ustekinumab and secukinumab.
  • Surgical interventions: In advanced cases, surgical removal is often necessary for symptom relief.

Although treatment may vary from person to person for managing acne inversa, it’s important to note that the only Food and Drug Administration (FDA)-approved biological treatments are the TNF-alpha inhibitor adalimumab and the monoclonal antibody secukinumab.

Acne vulgaris and acne inversa represent two distinct skin conditions that share some similarities. Acne vulgaris, characterized by clogged hair follicles, affects a wide range of people, particularly during adolescence. While it can be bothersome, it’s generally manageable with a variety of treatments.

On the other hand, acne inversa primarily impacts areas with apocrine sweat glands, leading to painful nodules, abscesses, and potentially severe discomfort. Managing this chronic condition is more challenging, often requiring a combination of treatments.

In both cases, early diagnosis and appropriate management are crucial. If you or someone you know is dealing with persistent skin issues, consulting a dermatologist is the first step toward relief and improved quality of life.