Summary
Acne vulgaris is a common skin disease that affects most individuals at some point in their lives. It is classified into different forms which vary in severity, lesion type, and localization, with the face commonly involved. The hallmark of acne are comedones, which can develop further into inflammatory papules, pustules, or even abscesses and nodules. Symptoms typically begin in early puberty and cease spontaneously during the third decade of life. There are multiple etiological factors: genetic predisposition, seborrhea, and hyperkeratosis are known to promote the development of acne. Topical and systemic treatment options are available to counteract inflammation and hyperkeratosis, as well as to help purify the skin.
Epidemiology
- Prevalence: the most prevalent chronic skin condition in the US [1]
- Age of onset: typically by 11–12 years, with symptoms usually disappearing around 20–30 years of age [2]
- Sex: more common in males during adolescence, but more common in women during adulthood
Epidemiological data refers to the US, unless otherwise specified.
Etiology
- Genetic predisposition [3]
-
Hormonal factors
- ↑ Androgens during puberty → increased production of sebum by sebaceous glands
- In women: menstrual cycle
- Follicular hyperkeratosis: Higher keratinocyte activity and decreased keratinocyte shedding in pilosebaceous units leads to the formation of comedones.
- Bacterial colonization with Cutibacterium acnes; (formerly known as Propionibacterium acnes) → inflammatory reactions with formation of papules, nodules, pustules, and/or cysts
- External factors
- Climate
- Drugs (e.g., anabolic steroids, progestin-only contraceptive pills, corticosteroids)
- Food [4]
Clinical features
- Localization: common in areas with sebaceous glands (predilection sites: face, shoulders, upper chest, and back)
-
Primary lesions
- Non-inflammatory: comedonal acne
- Inflammatory: affected areas are red and can be painful
- Papular/pustular acne: papules, pustules that arise from comedones
-
Nodular acne (> 5 mm in diameter)
- Commonly the back and neck
- Severe form: acne conglobata that is associated with cysts and abscesses
- Secondary lesions: : postinflammatory erythema, hyperpigmentation, and scarring
References:[5]
Subtypes and variants
Hidradenitis suppurativa
- Definition: inflammation of the hair follicles and apocrine glands, most likely triggered by a blockage
- Risk factors: obesity, smoking, family history
- Clinical presentation
-
Treatment
- Antibiotics, retinoids
- Reduce body weight, stop smoking
- If insufficient: incision, surgical removal with skin grafts for severe cases
Neonatal acne [6]
- Age of onset: : first few weeks of life
- Clinical presentation: : papulopustular rash
- Treatment: self-limiting disease ; no specific treatment
Infantile acne [6]
- Age of onset: ≥ 3 months
- Clinical presentation: papulopustular rash, closed comedones, and sometimes formation of nodules (more common in boys)
- Treatment: benzoyl peroxide, possibly in combination with erythromycin; in contrast to neonatal acne, treatment is indicated to avoid scarring
Acne fulminans [7]
- Definition: a rare, severe form of acne that is characterized by painful ulcerative skin lesions and systemic inflammatory symptoms
- Epidemiology
-
Etiology
- Adverse effect of isotretinoin (most common)
- Idiopathic
-
Clinical features
- Primary lesions
- Systemic manifestations
- Fever
- Myalgia
- Weight loss
- Arthralgia, arthritis
- Rarely hepatosplenomegaly, erythema nodosum, septic osteomyelitis
-
Diagnostics
- ↑ CRP, ↑ ESR
- Leukocytosis, thrombocytosis, anemia
- ↑ Liver enzymes
-
Treatment [8]
- Discontinue isotretinoin
- Initial monotherapy with systemic corticosteroids
- Subsequent combination therapy with oral corticosteroids and isotretinoin
- Treatment-resistant cases: cyclosporine, biologics (e.g., anakinra, secukinumab, ustekinumab), or dapsone
Treatment
Acne treatment [9]
| Severity | Treatment |
|---|---|
| Mild (e.g., comedonal) |
|
| Moderate (e.g., papular/pustular) |
|
| Severe (e.g., conglobata) |
|
Therapy is particularly important for patients with inflammatory acne to prevent complications such as scarring.
Retinoids [5][9]
- Main substance: isotretinoin (vitamin A derivative) given systemically
- Indication: in moderate to severe acne
- Mechanism of action: Retinoids normalize keratinization by inhibiting and modulating keratinocytes → ↓ sebum production
-
Contraindications
- Pregnancy, women of childbearing age without contraception: strong teratogenic effects
- Liver disease
- Simultaneous tetracycline treatment
-
Precautions (in all females of childbearing potential) [10]
-
1 month before initiating therapy:
- A serum/urine pregnancy test
- Two methods of contraception (oral contraceptive therapy + barrier contraception / IUD)
- During therapy: monthly pregnancy test and continuous use of two methods of contraception
- After completing therapy:
- Continue two methods of contraception for 1 month
- A pregnancy test at the end of 1 month
-
1 month before initiating therapy:
-
Side effects
- Dry skin, xerostomia, cheilitis, pruritus
- Headaches, arthralgias, alopecia, fatigue
- Congenital craniofacial anomalies (e.g., dysmorphisms, microtia, microphthalmia, cleft palate)
- Pericardial effusion, atrial tachycardia, congenital heart disease (e.g., great vessel anomalies)
- Thymic hypoplasia, PTH deficiency
- Congenital CNS defects (e.g., hydrocephalus, cortical blindness, microcephaly), idiopathic intracranial hypertension
- Laboratory test abnormalities
- Blood disorders (e.g., anemia)
- ↑ Triglycerides, ↓ HDL, ↑ glucose
- ↑ AST, ↑ ALT
Retinoid therapy should be discontinued at the latest one month before planned conception.