Acne 

Treatment and Followup
also see Pityrosporum Folliculitis

Clinical Features

• Acne vulgaris is the most common variety of acne and is the most prevalent skin condition in pediatrics.
• Occurs during two major age groups: newborn and adolescent
  • Neonatal acne: response to maternal androgen starting 2-4 weeks of age, lasting until age 4 to 6 mos; distribution – face, upper chest and back, similar to adolescent acne; persistence beyond 1 year can be associated with endocrine abnormalities; severe neonatal acne may predict severe adolescent acne
• Early lesions of acne (microcomedones) develop in 40% of children ages 8 to 10 years, primarily on the face
• 85% of adolescents will develop acne

 The lesions of acne 

• acne occurs in sebaceous follicles; obstruction of the sebaceous follicle produces the clinical lesions of acne
• In typical adolescent acne, several types of lesions are present at one time, such as open and closed comedones, inflammatory papules and pustules, excoriated lesions, and nodulocystic acne
• Neonatal acne presents with lesions in the same stage

 Open comedones (blackheads)

• obstruction occurs at the follicular mouth
  • the predominant lesion of adolescent acne
  • black color results from oxidized melanin within the stratum corneum plug, not from dirt
  • do not often progress to inflammatory lesions

Closed comedone (microcomedone, whitehead)

• obstruction of the sebaceous follicle just beneath the follicular opening
  • produces a cystic swelling; stratum corneum accumulates within the cystic cavern
  • may be the precursors to inflammatory acne
  • children 8 to 10 years of age often have microcomedones for many months before red papules or pustules are observed
• if open and closed comedones are the predominant lesion, the condition is  called comedonal acne

Inflammatory and cystic acne 

• inflammatory acne lesions include: firm red papules, pustules, nodules, cysts and, rarely, interconnecting draining sinus tracts
  • classified as mild, moderate, severe
    • mild: few to several inflammatory papules, pustules, and few to several nodules
    • moderate: several to many inflammatory papules, pustules, and few to several and a few to several nodules
    • severe: numerous/extensive inflammatory papules, pustules, and many nodules
• Cystic acne requires prompt treatment, because ruptured cysts or sinus tracts result in scar formation
  • New acne scars are highly vascular and have a red or purplish hue; they eventually regain normal skin color after several years
  • Acnes scars may be raised, flat or depressed; keloidal scars may occur

 Variants of acne in adolescents

• Friction acne from headbands, football helmets, baseball caps, tight bras or other tight fitting garments
• Oil-based cosmetics can result in predominantly comedonal acne
• Hair sprays and oil-based mousse produce acne along the scalp hair margin

 Drug induced acne

• Should be suspected  if all of the lesions are in the same stage at the same time, with involvement of the abdomen, lower back, arms and legs, in addition to the usual acne areas (face, upper chest and back)
• Drugs responsible for acne: androgens, ACTH, glucocorticoids, hydantoins, isoniazid

 Endocrine evaluation

• Warranted if the following are present: unusual acne, hirsutism, premature pubarche, or androgenic alopecia, especially when associated with obesity and/or menstrual irregularities
• Most common causes of hyperandrogenism in females
  • Functional ovarian and functional adrenal hyperandrogenism
  • Labs: free testosterone, dehydroepiandrosterone, and androstenedione
    • If any of these are elevated, do dexamethasone suppression testing to measure the response of free testosterone, dehydroepiandrosterone, and cortisol
  • Treatment: OCP, low dose glucocorticoids, antiandrogens

 Differential diagnosis

• Adolescent
  • Rosacea, steroid rosacea, flat warts, angiofibromas of tuberous sclerosis, molloscum contagiosum
  • Rosacea: prominent telangiectasia and a persistent flush to cheeks, nose or chin, as well as acne papules and pustules. In children, rosacea can result from potent topical glucocorticoids on the face
• Newborn: miliaria, nevus comedonicus (birthmark consisting of linear arrangement of open comedones)

 Pathogenesis

• Primary event: obstruction of the sebaceous follicle
• Stratum corneum lining the follicle is overproduced (androgen dependent)
• Sebaceous follicles contain 5-alpha-reductase which converts testosterone to dihydrotestosterone (DHT), a potent stimulus for cell nuclear division
• Inflammatory acne
  • Manipulation of a closed comedone can lead to rupture of contents into the dermis with a subsequent inflammatory response
  • Spontaneous inflammation also occurs in non-ruptured follicles; overgrowth of gram positive bacteria (Propionibacterium acnes or Staphyloccus epidermidis) may produce factors that initiate inflammation
  • Sebum is an unlikely cause of inflammation

Color Textbook of Pediatric Dermatology. 3^rd edition. 

Controversial new data (updated Feb 2009)

• Skim milk products may be related to acne, perhaps due to natural hormones found in pregnant cows. Kitavan Islanders and Ache hunter-gatherers have no acne, possibly due to a low glycemic load diet. Another study showed acne improvement with a high-protein, low glycemic load diet. Needs larger trials. Some highly regarded acne specialists like Guy Webster remain skeptical

Acne Toolbox Is So Full ‘The Top Won't Close’

Pediatric news
Volume 43, Issue 4, Page 20 (April 2009)
DAMIAN MCNAMARA

SINT MAARTEN, NETHERLANDS ANTILLES — New formulations of established oral agents and new combination products are available to treat acne, according to Dr. Hilary Baldwin.

The new oral formulations include extended-release minocycline tablets and delayed-release, enteric-coated doxycycline.

Long-term, yet-to-be published data on extended-release (ER) minocycline tablets (Solodyn) show a low number of adverse events over a 2-year period, Dr. Baldwin said at the Caribbean Dermatology Symposium. The agent does not appear to increase the risk of lupuslike syndrome, a concern some have with minocycline.

No cases of hyperpigmentation occurred among the 136 patients who completed the 2-year study. A total of 13 patients reported nausea and 8 had dizziness or vertigo.

ER minocycline is dosed to 1 mg/kg per day and maintains efficacy despite its lower dose, compared with other minocycline formulations, Dr. Baldwin said. “And food has no impact on absorption of the drug, which is important in our teenage boys who never stop eating.”

Both ER minocycline and delayed-release, enteric-coated doxycycline (Doryx) feature once-a-day dosing that should improve compliance, said Dr. Baldwin of the department of dermatology, State University of New York at Brooklyn.

DR doxycycline is slowly dissolved in the small intestine and features a lower potential for gastrointestinal upset, compared with other formulations of oral doxycycline, Dr. Baldwin said. The agent can be dosed once daily from 37.5 to 200 mg, she added.

In addition to the new oral agents, there is a new topical formulation—solubilized benzoyl peroxide. Solubilization is a chemical process that makes the benzoyl peroxide particle sizes smaller than even currently available micronized formulations. The tiny size and lipophilic and hydrophilic properties of solubilized benzoyl peroxide facilitate increased penetration into the follicle, Dr. Baldwin said. “Other forms of benzoyl peroxide have larger molecules, and you get clumps of [the drug] sitting on the skin.”

Solubilized benzoyl peroxide gel significantly reduced noninflammatory acne lesion counts, compared with a combination of 1% clindamycin and 5% benzoyl peroxide gel, according to a 12-week study by other investigators. There was no significant difference in inflammatory lesion counts between the two groups. The solubilized gel was slightly more irritating, Dr. Baldwin said, with significantly more stinging and burning in the first 4 weeks of treatment.

“The acne toolbox is so darn full the top won't close in 2009,” Dr. Baldwin said. She is a consultant, is an advisory board member, or is on the speakers bureau for Allergan, Galderma, GlaxoSmithKline, Graceway, Medicis, Ortho Neutrogena, Ranbaxy, Sanofi-Aventis, and Stiefel.

The new fixed-dose combination products for combatting acne include clindamycin 1.2%/benzoyl peroxide 2.5% (Acanya) gel, which provides a statistically significant improvement in noninflammatory lesions, compared with placebo, Dr. Baldwin said.

This formulation, approved by the Food and Drug Administration in October 2008, allows for a lower strength of the active ingredients, but there are no head-to-head comparisons yet, she said. The “benzoyl peroxide and clindamycin combination prevents an increase in resistance versus clindamycin alone, which did well up to 8 weeks but then resistance increased exponentially.”

According to a 12-month study presented as a poster at the meeting, a fixed-dose combination of adapalene gel 0.1% and benzoyl peroxide 2.5% is a safe and effective topical treatment for acne vulgaris. Dr. David M. Pariser, professor of dermatology at Eastern Virginia Medical School in Norfolk, was the lead author. He reported no relevant disclosures.

In December 2008, the FDA approved the retinoid adapalene and benzoyl peroxide combination (Epiduo gel) for the treatment of acne vulgaris in patients 12 years and older.

References:
TI Acne vulgaris: a disease of Western civilization. AU Cordain L; Lindeberg S; Hurtado M; Hill K; Eaton SB; Brand-Miller J SO Arch Dermatol 2002 Dec;138(12):1584-90.    

TI High school dietary dairy intake and teenage acne. AU Adebamowo CA; Spiegelman D; Danby FW; Frazier AL; Willett WC; Holmes MD SO J Am Acad Dermatol 2005 Feb;52(2):207-14.    

Cordain L, Lindeberg S, Hurtado M, Hill K, Eaton SB, Brand-Miller J. Acne vulgaris: a disease of Western civilization. Arch Dermatol. 2002 Dec;138(12):1584-90.

Webster GF. Commentary: Diet and acne. J Am Acad Dermatol 2008; 58: 794-5.