Ring-shaped Alopecia on the Scalp in a 3-month-old Infant

To Editor, A 3-month-old female patient presented with scalp alopecia, first noticed a few days after birth. She was delivered through cesarean section at 39 weeks of gestation to a 27-year-old mother, who was gravida 3, para 1, with one previous abortion. At birth, there were no indications of caput succedaneum (CS), such as edematous swelling of the scalp. The mother reported no additional illnesses or use of medications during the pregnancy. The family reported that there was no birth trauma, prolonged labor during the antepartum period or delivery, or any risky conditions such as hair traction. The patient’s mother noted that the baby often slept in a prone position and that there had been no prolonged pressure on the scalp from wearing a hat or cap. Dermatological examination revealed a 3–4 cm wide halo-shaped band of alopecia encircling the scalp [Figure 1]. The skin appeared normal except for the area affected by alopecia.Figure 1: Halo band of alopecia in the occipital regionBased on the patient’s history and clinical presentation, the diagnosis was consistent with halo scalp ring (HSR). The term HSR, initially defined by Neal et al. in 1984, describes an annular pattern of scalp alopecia that arises during the perinatal period. HSR may manifest as transient, nonscarring hair loss or, in some cases, as permanent alopecia.[1,2] HSR is either present at birth or develops shortly thereafter. It manifests as a band of alopecia, typically 1–4 cm wide, although cases with widths of up to 9 cm have also been reported. This condition is commonly located around the site of CS, particularly in the vertex region.[3] HSR is most frequently observed in neonates born to primigravida mothers, particularly following a complicated delivery and is often associated with the presence of CS.[2] CS is a subcutaneous serohematous extravasation on the scalp that generally has a favorable prognosis, resolving within a few days without lasting effects. It occurs as a result of mechanical pressure exerted by the uterus, cervix, or vaginal structures during the process of delivery.[1] In cases where the pressure is insufficient to cause CS but strong enough to result in localized damage, alopecia may develop.[2] Hair loss typically remains mild, with gradual regrowth expected if the injury is not severe.[1-3] However, a severe hemorrhagic CS can lead to scarring alopecia.[4] HSR is a benign condition and does not warrant additional investigations for central nervous system abnormalities.[2] The differential diagnosis encompasses conditions such as aplasia cutis congenita, neonatal occipital alopecia, pressure-induced alopecia, and alopecia areata. In infants, aplasia cutis congenita typically manifests as scarring alopecia and frequently requires additional diagnostic assessment.[5] No treatment was prescribed for the alopecia. After 8 months, the hairless patch had completely recovered. By the time, the patient was 20 months old, the previously hairless area was fully resolved [Figure 2].Figure 2: By the time the patient was 20 months old, the previously hairless area was fully resolvedHSR should be considered in the differential diagnosis of newborn alopecia. We propose that HSR is a common condition in infants and it is essential for pediatricians and dermatologists to recognize this form of alopecia. Declaration of consent The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s)/guardian(s) of the patient. In the form, the parent(s)/guardian(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child/children will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.