There are many types of acne in childhood, the pathogenesis is complex, the diagnosis needs to exclude diseases of the endocrine system, and the treatment should pay attention to the effects of drugs on children’s development. This article provides a brief description in these areas.
The occurrence of acne is related to a variety of factors, such as the body’s androgen metabolism, exposure to the environment, genetics and other factors. The metabolism of androgens in children is different from that of adults, and in addition, environmental influences are significantly different from those of adolescence.
I. Classification of acne in childhood
Fetal androgens?
Exposure to pro-acne forming substances, emollients most common
Topical or systemic application of corticosteroids
Exposure to diflubenzin-related substances
Maternal ingestion of ethinyl urea
Masculinizing luteinizing tumors during pregnancy
II. Neonatal acne
The development of neonatal acne may be related to endocrine changes during pregnancy. The adrenal glands of newborns are relatively large and can produce β-hydroxylated steroids, which can stimulate sebaceous gland proliferation. In addition, some newborns have increased testicular production of androgens, mainly testosterone, so neonatal acne is also related to changes in the hormones of the newborn itself.
Neonatal acne occurs at birth or shortly after birth and is more common in males. The lesions are most common on the face, most often on the cheeks and forehead, but may also invade the back and groin. The lesions appear as a small number of closed pimples and occasionally open pimples, papules and pustules. Thomas suggests that about 20% of newborns have neonatal acne if a small amount of acne is used as a diagnostic criterion for neonatal acne [1].
Neonatal acne is usually mild and spontaneous and usually does not require treatment, and if needed, erythromycin ointment can be used for rashes with significant inflammation.
III. Infantile acne
The cause of infantile acne is unclear. Some children have elevated levels of luteinizing hormone, follicle-stimulating hormone and testosterone. Therefore, infantile acne may be related to abnormalities in hypothalamic function. Recent studies have shown that increased androgens of adrenal origin can cause acne in female infants.
Infantile acne occurs in infants between 6 and 16 months of age, mostly between 6 and 9 months of age, and is more common in males. The lesions are usually confined to the face, with the cheeks being the most pronounced. In addition to pimples, lesions may include papules, pustules, nodules and cysts, and scarring after healing. The inflammation of acne is obvious and lasts for a long time. Some cases disappear after 1 to 2 years of age, most last until 4 to 5 years of age, and very few can last until puberty. Classification of infantile acne according to the Kligman acne grading scale shows that 62% of patients have moderate acne, with mild and severe acne accounting for 24% and 17% of the total, respectively. Patients who have had infantile acne generally have more severe acne during adolescence, and parents may also have a history of severe acne.
Treatment is the same as for acne vulgaris. Oral antibiotics are given when inflammation is evident, and erythromycin, 125-250 mg/d, 2 times/d, is the main choice at this age. Methotrexate, 100 mg, 2 times/d, can be added if there is resistance to erythromycin. Cunliffe [3] et al. used this method to treat 18 cases of childhood acne with topical antibiotics and obtained satisfactory results. Cystic damage can be treated with topical injection of 2.5 mg/ml of tretinoin. For cases that cannot be controlled by the above methods, the use of oral isotretinoin has been reported abroad at 0.5 mg/kg/d for 4-5 months, with short-term efficacy, but long-term side effects are unclear [3, 4, 5]. The parents of the child should also be informed that treatment is a long-term process and that recurrence will occur during adolescence.
IV. Acne in preschool children
Acne in preschool children occurs between the ages of 1 and 7 years and is clinically rare, and attention should be paid to whether the patient has hyperandrogenemia.
The differential diagnosis includes Cushing’s syndrome, congenital adrenal hyperplasia, gonadal or adrenal tumors, and early puberty. Bone age, growth charts, blood total testosterone, free testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate, luteinizing hormone and follicle stimulating hormone, prolactin and 17α-hydroxyprogesterone should be measured clinically. It has also been reported that D-actinin can contribute to the development of acne. Acne in preschool children sometimes needs to be differentiated from hair keratosis and cornea on the cheek. Treatment is the same as for infantile acne.
V. Prepubertal acne
Prepubertal acne is a type of acne that occurs before the appearance of pubertal signs and has a clear genetic predisposition. Acne is the first sign of pubertal maturation. Maturation of adrenal function and testicular and ovarian function are two factors that contribute to pubertal development. Abnormalities in both factors lead to early pubertal development, the appearance of pubertal signs, and the generation of prepubertal acne. Studies have shown higher blood levels of dehydroepiandrosterone sulfate in prepubertal female acne patients.
Prepubertal acne predicts the severity of acne during puberty. Girls with severe acne during puberty may develop a large number of pimples three years before their first menstrual period and have high levels of dehydroepiandrosterone sulfate in their blood early on, as well as a high rate of sebum production. The most common sites of prepubertal acne are the mid-forehead, nose, and chin, where acne damage is predominant. After puberty, the lesions increase and inflammation worsens, resulting in severe acne vulgaris.
The differential diagnosis requires the exclusion of drug-induced acne-like rashes. In persistent refractory cases, various hormone levels in the blood should be measured to find the cause of the disease. Patients with adrenal origin can take oral corticosteroids, and patients with polycystic ovaries can take oral contraceptives, such as cyproterone acetate, or spironolactone.
VI. Other types of acne in children
1. Infantile acne vulgaris
Infantile comedonal acne is rare clinically, and the damage occurs mainly on the face. The lesions are similar to those of adult comedonal acne, and there can be nodules, cysts, sinus tracts and scarring left after inflammation. It is easily diagnosed clinically, but needs to be differentiated from different causes of impetigo and seborrhea.
In addition to the treatment options for the conventional management of infantile acne, there are foreign case reports of oral retinoic acid, isotretinoin, 0.3 to 0.7 mg/kg/d for 4 to 6 months [4], with satisfactory efficacy, but no long-term safety evaluation has been seen. In addition to the large number of known side effects, isotretinoin may delay bone growth and thus affect the growth and development of infants.
2. Infantile toxic acne
A large number of topical skin cosmetics and medications can lead to the development of acne, mainly including ointments, creams, hair lotions, and mineral oils. Toxic acne in infants is mainly seen in African Americans and people from the Mediterranean region. Because acne-promoting substances take time to produce specific symptoms, children are born normal and develop acne in the first few months, mainly as open or closed acne on the forehead, temporal area, cheeks, and back of the nose. The lesions can also occur on the upper and lower extremities and trunk and are mainly associated with contact sites and can therefore be differentiated from infantile acne.
Acne can be self-resolving after stopping the use of acne-promoting substances and does not require treatment. If recovery is slow, topical medications such as retinoic acid and azelaic acid can be used.
3. Steroidal acne
Steroidal acne can occur in both adults and children as a result of local or systemic steroid application. Since children have fewer fully developed hair follicles, steroidal acne is less common than in adults. The lesions appear as a large number of clustered inflammatory papules and pustules, uniform in size and small in diameter, with few blackheads and pimples. Clinical studies have shown a correlation between the severity of steroidal acne and the amount of steroid absorbed. Treatment can be topical with benzoyl peroxide and retinoids.
4, chloracne
Human exposure or ingestion of aromatic hydrocarbons containing chlorine groups can lead to the development of acne, which is called chloracne. The literature reports the prevalence of such acne in Italy, Spain, Japan and Taiwan. Chlorinated aromatic hydrocarbons are strong acne-promoting substances that can contaminate soil, crops, air and water. Human exposure includes direct skin contact, inhalation or ingestion and can occur in both children and adults. Clinical manifestations include the appearance of scattered, firm and persistent pimples, sometimes forming pustules, papules and cysts after exposure. It occurs primarily on the face, with some patients having hand involvement.
The treatment is the same as that for acne vulgaris, often requiring isotretinoin, and the prognosis is easy to leave scarring.
5.Fetal endourea syndrome
Fetal acetonide syndrome is caused by the maternal use of sodium phenytoin for epilepsy during pregnancy. Acne is a manifestation of the syndrome, which occurs mainly on the face, is self-limiting, and the lesions are mainly papules and pustules. Patients are also associated with physical and mental retardation, abnormal craniofacial bone development, hypertrophy of the ends of the toes and dry hair manifestations. There are also some patients with fetal endometriosis syndrome with mild symptoms, which are easily ignored.
6. Infantile acne induced by androgenic luteinoma during maternal pregnancy
During gestation, the maternal ovaries develop a persistent functional corpus luteum, which continuously produces androgens. The mother shows signs of masculinization, including acne, increased sebum production, hirsutism and a thickened voice. Female infants may show signs of masculinity, acne and mild hirsutism. Diagnosis of androgenic luteinizing tumors in pregnancy requires ultrasound of the ovaries and peripheral blood androgen measurement. Ultrasound may reveal ovarian masses and increased levels of peripheral blood androgens. Removal of excess corpus luteum during pregnancy is curative.