Evolving Scalp Lesions in an 8-day-old Infant

Abstract

An 8-day old girl is referred to the emergency department (ED) by her pediatrician with concern for an infected scalp lesion. The birth history is notable for a pregnancy complicated by obesity and severe pre-eclampsia. The infant was born at 37 weeks’ and 5 days’ gestation following 3 days of latent labor and 10 hours of active labor prior to conversion to cesarean delivery due to arrest of dilation. There was no scalp electrode monitoring before delivery nor known scalp trauma sustained during the cesarean delivery. Maternal group B streptococcus screening was positive, and adequate penicillin prophylaxis was administered. Membranes were ruptured for 20 hours prior to delivery, and amniotic fluid was clear. Based on laboratory tests and application of the Neonatal Early-Onset Sepsis Calculator, (1) the patient was deemed low risk for sepsis. The physical examination was notable for significant caput succedaneum and scalp bruising; however, no discrete lesions, skin defects, or lacerations were noted. The patient underwent phototherapy on day 3 for physiologic hyperbilirubinemia, likely exacerbated by the scalp bruising. The infant was fed by breast and bottle and had a normal 7% weight loss at discharge. The mother and infant were discharged together on day 4 with no other complications during the hospitalization.The infant is seen in the primary care office at the age of 6 days and is noted to have a foul-smelling lesion on her posterior occipital scalp with an overlying crust (Fig 1). She is referred to the ED where the wound is felt to be an infected laceration that likely occurred due to birth trauma that was not recognized during her newborn hospitalization. Ultrasound of the scalp to assess for an associated abscess was negative. The infant was afebrile and well appearing without signs of systemic infection. She was discharged with recommendations to apply bacitracin to the wound.The infant presents again to the ED at 8 days of age with drainage from her scalp noted at home as well as new scalp lesions (Figs 2 and 3). Examination demonstrates a deep-appearing, gaping furrow approximately 3 mm deep and 1 cm in length. It is moist but without drainage in the occiput with a contiguous, superficial yellow crusted linear lesion extending laterally approximately 3 cm. There are additional dark, scaly, crusted annular and ovoid plaques ranging from 0.5 to 1 cm in diameter located on the right fronto-parietal scalp and left parietal scalp, which are difficult to appreciate due to thick, dark hair. The infant continues to be otherwise well appearing, afebrile, and feeding well at the breast with appropriate weight gain. Gram-stain from a swab of the occipital lesion reveals polymorphonuclear cells without bacteria. Wound culture and herpes simplex virus (HSV) polymerase chain reaction test from the primary lesion were sent. The birth history and clinical course confirmed the diagnosis.The differential diagnoses for unusual scalp lesions in a well-appearing neonate include the following: a birth defect such as cutis aplasia; an open or draining abscess; an autoimmune condition such as neonatal lupus; an iatrogenic birth injury such as from vacuum extraction or a scalp electrode; and pressure necrosis from birth trauma known as a halo scalp ring.Halo scalp ring is a birth trauma that results from protracted pressure on the vertex of the scalp against the cervix during a prolonged delivery. (2) Caput succedaneum describes the typical edema and contusion of the newborn scalp due to pressure on the skin. Infrequently, such pressure can cause necrosis of the scalp as a result of locally reduced blood flow and focal hypoxic-ischemic injury to the involved tissue. (3)(4) The pressure injury can range from mild to full-thickness necrosis and can result in distinctive annular alopecia. (3) If the initial injury is minor, the hair loss may resolve within months to years; if the injury is severe, scarring alopecia may result in permanent hair loss. (3) The incidence of halo scalp ring is unknown and believed to be underreported due to underrecognition.Clues to the diagnosis include a pattern of skin findings with alopecia or ulcerated skin in a linear or curvilinear pattern (5) with an overall annular appearance over bony prominences (a halo). (6) The diagnosis is supported by the history of prolonged labor in a primigravid with resulting caput succedaneum and molding noted during birth hospitalization. Recognition of this diagnosis is reassuring and no further evaluation for alternative diagnoses or congenital anomalies is necessary. (6) Treatment is primarily supportive with attention to wound care based on the extent of the injury. Occasionally, keratinocyte grafting may be used to treat large ulcerations. (3) Residual scar excision, if present, is deferred until school age and may be considered for cosmetic outcomes. (3) Secondary infection may occur at sites of pressure necrosis, most commonly with skin flora such as Staphylococcus and Streptococcus species. (5) Given recent passage through the birth canal, enteric flora may also be recovered but are of uncertain significance.Diagnosing halo scalp ring is challenging if the full halo is not present; however, if the full halo is appreciated, the differential diagnosis is limited. Our patient appeared to present initially with an isolated ulceration or fissure on her occiput. Additional diagnoses that were considered at that time included aplasia cutis congenita (ACC), iatrogenic birth trauma, and neonatal herpes infection. ACC is a rare birth defect defined as congenital absence of skin. It most commonly occurs on the scalp, frequently on the vertex near the hair whorl, but can occur anywhere on the skin of the body. Scalp lesions are most frequently isolated; only 20% of patients have 2 lesions and 8% have 3 lesions. (7) Scalp lesions are classified in 2 subtypes: membranous and nonmembranous. (7) Membranous lesions have a sharply demarcated appearance with a membrane apparent in a round or oval-shaped defect. (7) Nonmembranous lesions, more common in familial forms of ACC, are frequently larger, irregular, and stellate in appearance. (7) These lesions tend to heal with a scar. Recognizing ACC is important as there can be underlying or associated conditions for which additional treatment and evaluation may be warranted.Iatrogenic birth injuries to the scalp can result from many different etiologies. Fetal scalp monitors may cause superficial soft-tissue injury. Scalp electrodes are typically placed in the vertex scalp and result in an isolated lesion. Localized infection may occur. (8) The most notable infection risk associated with scalp electrodes is introduction of HSV. HSV can also be introduced in the peripartum period in the absence of a scalp monitor, frequently at the presenting fetal part which has had prolonged contact with the cervix, most commonly the vertex scalp. Intrauterine acquisition of HSV, which results in congenital HSV, is a rare presentation and accounts for only 5% of neonatal HSV. (9) Congenital HSV is associated with multisystem involvement. Skin findings are present at birth or manifest within 72 hours and include vesicles, bullae, scars, and erosions or aplasialike lesions. (10) Scalp lacerations may occur during cesarean delivery when the obstetrician opens the uterus. They are typically sustained at the presenting part of the fetus and are more common in emergent cesarean deliveries. (11) Scalp lacerations may also complicate vacuum extraction due to shearing forces. (8)In our case, the primary lesion evolved, and additional lesions appeared leading us to broaden the differential diagnosis to include neonatal lupus and Langerhans cell histiocytosis (LCH). Neonatal lupus erythematosus is a rare condition that occurs due to maternal autoantibodies acquired across the placenta. (12)(13) Neonatal lupus erythematosus may occur in the absence of a maternal diagnosis of systemic lupus erythematosus and the hallmarks of the condition are rash and heart block. The rash is typically a macular annular or elliptical erythema though may be papular or plaquelike and occasionally has a central clearing or fine scale. (12) The rash is rarely present at birth and becomes apparent within 4 to 6 weeks, often after sun exposure. (13) The rash is most commonly located on the head or scalp and less commonly appears on the trunk or extremities. (12) LCH is a rare disorder, which can affect multiple organs and cause a wide variety of skin manifestations including crusted or scaly nodules and papules, blisters, plaques, and ulcerations; lesions may occur on the scalp as well as face, trunk, buttocks, and intertriginous areas. (14) Skin biopsy demonstrates Langerhans cells with typical features.The initial appearance of the scalp lesions was atypical and did not elicit recognition of a halo scalp ring. Dermatology was consulted and a biopsy was obtained. Pathology was consistent with nonspecific trauma and there was no evidence of LCH. HSV polymerase chain reaction was negative. Wound culture was notable for light growth of Escherichia coli, which was likely a colonizing or contaminating organism as there was no fever, or systemic illness, and no change in the appearance of the scalp lesions after receiving 48 hours of intravenous cefotaxime. Plastic surgery was consulted for management and recommended wound care with saline-soaked gauze to remove the crust along with application of mupirocin. The infant subsequently followed up with plastic surgery at 4 months of age at which time the posterior scalp lesion was healed; however, she continued to have alopecia at the site of an anterior scalp lesion (Fig 4). She will continue to follow-up with plastic surgery for possible future scar revision if alopecia does not resolve.