{
 "topic": "Acne Vulgaris",
 "slug": "acne-vulgaris",
 "category_id": 15519,
 "summary": "Acne across the pediatric age spectrum - neonatal, infantile, and adolescent acne vulgaris - with pathogenesis, distinguishing features, and age-appropriate topical-to-oral treatment escalation.",
 "written_by": "claude-sonnet",
 "references": [
  {
   "title": "Cover",
   "author": "Vitalsource Download",
   "pages": [
    4983,
    4992
   ]
  },
  {
   "title": "MedStudy Pediatrics Core 11th Edition 2024-2025",
   "author": null,
   "pages": [
    836,
    851
   ]
  },
  {
   "title": "Kliegman R. Nelson Textbook of Pediatrics 2-Volume Set 22ed 2024",
   "author": null,
   "pages": [
    4219
   ]
  },
  {
   "title": "Netters Pediatrics (Florin Т., Ludwig St.)",
   "author": null,
   "pages": [
    821
   ]
  },
  {
   "title": "The Harriet Lane Handbook (The Johns Hopkins Hospital)",
   "author": null,
   "pages": [
    251
   ]
  },
  {
   "title": "The Harriet Lane Handbook 22nd Edition (2020) (The Johns Hopkins Hospital)",
   "author": null,
   "pages": [
    251
   ]
  },
  {
   "title": "Ghai Essential Pediatrics, 9e (Vinod K Paul, Arvind Bagga)",
   "author": "CamScanner",
   "pages": [
    690
   ]
  },
  {
   "title": "Pediatric Clinical Practice Guidelines & Policies, 18th Edition",
   "author": "American Academy of Pediatrics",
   "pages": [
    893
   ]
  }
 ],
 "short": [
  {
   "title": "In short",
   "content": "- Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous unit affecting about 85% of people aged 12-24; onset is typically 12-14 years, earlier in girls, with lesions subsiding by the early third decade in about 70% of subjects.\n- Four main pathogenic factors: increased sebum production, abnormal follicular keratinization, Cutibacterium acnes (formerly Propionibacterium acnes) proliferation, and inflammation. Risk factors include androgens, family history, and stress; there is no strong evidence that diet affects acne.\n- Lesions include noninflammatory closed comedones (whiteheads) and open comedones (blackheads), plus inflammatory papules, pustules, and, in severe disease, cysts or nodules, typically on the face, shoulders, chest, and back. Nodulocystic acne is more common in males.\n- Neonatal acne (neonatal cephalic pustulosis) appears in the first 2-4 weeks of life as small pink papules/pustules on the face and scalp without comedones, is linked to Malassezia furfur, and resolves spontaneously within about 1-3 months with only routine skin cleansing.\n- Infantile acne is a true acne, presenting at about 6 weeks to 6 months of age with open comedones and variable papules/pustules on the cheeks and chin, driven by transient adrenal androgen production (and abnormal testosterone levels in boys); it can last 1-2 years and causes scarring in up to 25% of cases.\n- First-line treatment for typical adolescent acne is topical: retinoids, benzoyl peroxide, and/or topical antibiotics; oral erythromycin is an option for severe/recalcitrant disease (oral tetracyclines are contraindicated in young children due to tooth discoloration); isotretinoin is reserved for the most severe cases.\n- Infantile acne is treated with a topical retinoid (tretinoin cream or adapalene gel) plus benzoyl peroxide; oral erythromycin or azithromycin can be added for more severe/refractory cases, and oral isotretinoin has been used for severe nodular variants.\n- Most infantile acne does not need hormonal workup, but unusually persistent or severe infantile acne may warrant a complete endocrine evaluation for abnormal androgen or cortisol production.\n"
  }
 ],
 "long": [
  {
   "title": "Definition",
   "content": "Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous unit with a multifactorial pathogenesis. It is the most common skin problem of adolescence but can occur at any age, including infancy and early childhood.\n"
  },
  {
   "title": "Epidemiology",
   "content": "Acne vulgaris affects approximately 85% of individuals between 12 and 24 years of age, occurring in almost all peripubertal children. Typical age of onset is 12-14 years, earlier in girls; in about 70% of subjects, lesions subside by the early third decade. Both sexes are affected equally overall, though nodulocystic acne is more frequent in males. The degree of involvement is highly variable, ranging from mild, transient disease to severe disease causing significant scarring and emotional distress.\n"
  },
  {
   "title": "Etiology and Pathogenesis",
   "content": "Four main pathogenic factors drive acne: increased sebum production, abnormal keratinization of the follicular infundibulum, proliferation of Cutibacterium acnes (formerly Propionibacterium acnes) within the pilosebaceous unit, and inflammation. Recognized risk factors include androgens, family history, and stress; there is no strong evidence that dietary habits affect acne. The earliest lesion, the microcomedone, is thought to arise from abnormal follicular keratinization.\n"
  },
  {
   "title": "Clinical Features",
   "content": "Acne can present at multiple life stages, each with a distinct pattern. Neonatal cephalic pustulosis (formerly neonatal acne) appears within the first 2-4 weeks of life as multiple 1-2 mm dusky pink papules and pustules on the face and scalp, without comedones; it is thought to be a hypersensitivity response to Malassezia furfur (formerly Pityrosporum ovale/orbiculare) on the skin and resolves spontaneously within about 1-3 months, not associated with scarring. Infantile acne is a true form of acne presenting typically between 6 weeks and 1 year of life (some sources cite onset at 3-6 months), characterized by open comedones with variable papules and pustules over the cheeks and chin; severe nodular forms are rare but scarring occurs in up to 25% of cases, and the course can last 1-2 years. Typical adolescent acne vulgaris presents with a mix of noninflammatory lesions - closed comedones (whiteheads: white/skin-colored papules without erythema) and open comedones (blackheads: dilated follicles filled with keratinocytes, oils, and melanin) - together with inflammatory papules, pustules, and, in more severe cases, cysts or nodules, distributed on the face, shoulders, chest, and back.\n"
  },
  {
   "title": "Diagnostics",
   "content": "Diagnosis is clinical, based on the characteristic lesion morphology and distribution at the appropriate age. In neonates presenting with facial pustules, it is important to exclude bacterial, viral, or fungal causes, as well as other benign neonatal conditions such as milia, erythema toxicum neonatorum, transient neonatal pustular melanosis, and sebaceous gland hyperplasia. Most infantile acne, in the absence of other signs of androgen excess, does not require hormonal workup; however, unusually persistent or severe infantile acne should raise concern for abnormal androgen or cortisol production and prompt consideration of a complete endocrine evaluation.\n"
  },
  {
   "title": "Treatment",
   "content": "For typical adolescent acne, first-line treatment is topical therapy: retinoids, benzoyl peroxide, and/or topical antibiotics. In severe or recalcitrant cases, oral erythromycin is an option; oral tetracyclines are contraindicated in young children because of the risk of tooth discoloration. Isotretinoin has demonstrated efficacy and is reserved for the most severe cases. For infantile acne, a topical retinoid (such as tretinoin cream or adapalene gel) combined with benzoyl peroxide is recommended first-line, with oral erythromycin or azithromycin added for more severe or refractory disease; oral isotretinoin has been used for severe nodular variants. Neonatal acne requires no specific treatment beyond routine daily cleansing with soap and water.\n"
  },
  {
   "title": "Complications",
   "content": "Scarring is a recognized complication, particularly of infantile acne (up to 25% of cases) and of severe cystic/nodular adolescent acne. Beyond physical scarring, acne can cause significant emotional distress in affected adolescents.\n"
  }
 ],
 "clinical": [
  {
   "title": "Distinguishing Acne by Age of Presentation",
   "content": "In a neonate with facial pustules in the first 2-4 weeks of life, favor neonatal cephalic pustulosis (comedones are absent) when the picture is small, uniform dusky-pink papules/pustules on the face and scalp - but still actively exclude bacterial, viral, or fungal causes and consider other neonatal mimics such as milia, erythema toxicum neonatorum, transient neonatal pustulosis, and sebaceous gland hyperplasia. Manage neonatal acne with routine cleansing alone and reassure caregivers it resolves spontaneously within about 1-3 months without scarring. In an infant presenting between about 6 weeks and 1 year of age with open comedones and papules/pustules on the cheeks and chin, diagnose infantile acne - a true acne with a course that can last 1-2 years and a meaningful scarring risk (up to 25% of cases), so start treatment rather than only observing. Reserve hormonal/endocrine workup for infantile acne that is unusually severe or persistent, or accompanied by other signs of androgen or cortisol excess; routine hormonal testing is not needed otherwise.\n"
  },
  {
   "title": "Treating Acne Across Severity",
   "content": "Start typical adolescent acne on topical therapy - a retinoid, benzoyl peroxide, and/or a topical antibiotic - as first line. For infantile acne, use a topical retinoid (tretinoin cream or adapalene gel) combined with benzoyl peroxide as the initial regimen. Step up to oral therapy for severe or recalcitrant disease at either age: oral erythromycin (or azithromycin in infants) for more severe or refractory cases, avoiding oral tetracyclines in young children because of tooth discoloration. Reserve oral isotretinoin for the most severe, scarring, or nodular disease at any age. Counsel adolescents and families early about the risk of scarring and the emotional impact of acne, since both are recognized complications that argue for prompt, adequate treatment rather than a wait-and-see approach in more than mild disease.\n"
  }
 ]
}