Infantile Acne

Etiology

The precise etiology of infantile acne has yet to be determined. Current theories include genetic predisposition and heightened sebaceous gland activity in response to normal levels of circulating androgens (adrenal androgens in female infants; both adrenal and testicular androgens in male infants).[11][7][9] In rare cases, infantile acne can be a sign of an adrenocortical tumor, and there are case reports of Malassezia as a cause of infantile acne.[12][13] 

Epidemiology

Infantile acne is relatively uncommon and affects less than 2% of children.[14][15] Relatively recent data derived from the outpatient pediatric population of the United States from 2000 to 2010 revealed that approximately 9.2 million ambulatory clinical visits each year were attributed to pediatric acne alone, with neonatal and infantile acne accounting for 3% of all cases.[16] Infantile acne can affect either sex but has a higher predominance in males.[5][17]

History and Physical

First establish the diagnosis of infantile acne by confirming the presence of comedones, located primarily of the facial region in a patient between 6 weeks to approximately 12 months of age. Lesions most commonly appear on the cheeks and less commonly on the chest and back.[6] Next, determine the severity by documenting the presence of other inflammatory lesions such as pustules, nodules or cysts and the actual extent of lesion distribution. Finally, a thorough physical examination should include an evaluation for possible evidence of an underlying endocrine disorder; this involves reviewing past and present growth patterns, along with an assessment of breast development, testicular enlargement (or clitoromegaly), abnormal presence of pubic hair or features of hirsutism.[4][18][7]

Evaluation

Infantile acne characterized by a relatively rapid onset, determined to be subjectively severe in nature, or accompanied by any physical findings suggestive of hyperandrogenism (hirsutism, abnormal presence of pubic hair, testicular enlargement or clitoromegaly) could indicate the presence of an underlying androgen-secreting (or corticosteroid-secreting) disorder. As such, further evaluation is reasonable and often warranted, along with a referral to a pediatric endocrinologist. Additional investigations may include, but are not limited to, assessment of bone age and measurement of serologic levels of dehydroepiandrosterone-sulfate (DHEAS), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and free testosterone.[11][4][18][7]

Treatment / Management

In general, most patients diagnosed with infantile acne have a moderate course at best requiring no treatment, resolving within 6 to 12 months of initial onset. However, some cases can be severe enough to warrant the initiation of medication. Due to a lack of high-quality clinical trials, especially from randomized controlled trials, there are no USFDA-approved medications for the treatment of acne vulgaris in patients under the age of nine.  As such, recommendations regarding therapeutic intervention for infantile acne derive from empiric observations of both adolescent and adult populations. Simply stated, the treatment of infantile acne is essentially the same therapeutic approach for acne vulgaris of any age.[7][10][14](B3)

For mild infantile acne, start with a topical agent such as a topical retinoid or benzoyl peroxide. They can be used as monotherapy or in combination. For mild inflammatory acne, the addition of a topical antibiotic (e.g., erythromycin or clindamycin) to the regimen above would be appropriate. Remember to avoid using a topical antibiotic as a monotherapy for acne of any age given the growing emergence of resistant bacterial strains of Propionibacterium acnes. In particular, simultaneous use of benzoyl peroxide, given its inherent nonspecific antimicrobial activity, has shown to be effective in preventing this trend.[16][18]

For moderate to severe inflammatory lesions, especially with the presence of or growing concerns for scarring, the next option should be the administration of oral non-tetracycline antibiotics. First-line should be erythromycin. If the patient has documented colonization of a resistant strain of Propionibacterium acnes, then an acceptable alternative is sulfamethoxazole-trimethoprim. Remember to avoid the systemic use of tetracycline-derived antibiotics in children less than 8 years of age given the risk of discoloration of the permanent dentition. Additional treatment options beyond the above also include intralesional triamcinolone (2.5 mg/mL) injections for isolated nodules and cysts. For cases of infantile acne that are particularly severe and considered intractable to all the above, judicious administration of oral isotretinoin is deemed reasonable to prevent further permanent physical and psychosocial sequelae. As with adolescent and adult patients, treatment with oral isotretinoin should include close monitoring, both clinically and with laboratory diagnostics. Both a fasting lipid profile and liver function test should be obtained at baseline and on a routine basis throughout its administration. It may also be prudent, depending on the original clinician’s level of expertise, to consult a dermatologist before initial administration.[3][4][18][8][9]

Differential Diagnosis

When evaluating an infant for acne-like skin lesions, differential diagnoses to consider include:

• Periorificial dermatitis
• Keratosis pilaris
• Exogenous agents (steroid acne, acne pomade, chloracne)
• Infections (e.g., molluscum contagiosum) 

Prognosis

As mentioned previously, most patients diagnosed with infantile acne have a moderate course at best, resolving without treatment by 1 to 2 years of age. However, some cases can be severe enough to warrant the initiation of medication. If care is taken by the clinician to ensure an accurate diagnosis, initiation of the appropriate level of treatment when warranted, and active engagement and education of the parent or caregiver, even severe cases of acne can have excellent outcomes. As such, the overall prognosis for infantile acne is still considered excellent.

Complications

Possible complications of infantile acne generally encompass residual changes to the skin that vary from reversible to permanent. Skin changes that usually resolve with both appropriate treatment and the tincture of time include residual erythema and, in patients with darker skin tones, postinflammatory hyperpigmentation (PIH). It is essential to remind caregivers that even though the original acne has cleared, such complications can still take months to resolve.

With more severe forms of inflammatory infantile acne, the risk of permanent scarring and potential for resultant psychosocial issues is higher. This risk can be mitigated with timely and accurate diagnosis and initiation of the appropriate level of treatment. However, although not common, despite early diagnosis and timely, maximal-level treatment some infants may continue to have a protracted and recalcitrant course. These particular patients may even experience active lesions for several years beyond infancy, possibly into the onset of puberty and progressing into a more form severe adolescent acne.[18][6][7][8]