Case Series

Cold Abscesses of the Newborn: A New Pathogenetic Hypothesis

by Alessandra Gelmetti1,2*, Silvia Galletti1,3, Luigi Tommaso Corvaglia1,3, Bianca Maria Piraccini1,2, Filippo Viviani1, Marco Adriano Chessa1,2, Iria Neri2

1Dermatology Unit, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy

2Dermatology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy

3Neonatal Intensive Care Unit, IRCCS S. Orsola-Malpighi Hospital, Bologna, Italy

*Corresponding author: Alessandra Gelmetti, Department of Medical and Surgical Science, Alma Mater Studiorum University of Bologna, Via Massarenti 5, Bologna (BO), Italy

Received Date: 17 July 2023

Accepted Date: 24 July 2023

Published Date: 28 July 2023

Citation:Gelmetti A, Galletti S, Corvaglia LT, Piraccini BM, Viviani F, et al (2023) Cold Abscesses of the Newborn: A New Pathogenetic Hypothesis. Clin Exp Dermatol Ther 8: 208.


Objective: Cold abscesses of the newborn are a benign and probably underdiagnosed condition. Affected patients are immunocompetent newborns without any previous history of pregnancy complications or systemic conditions. Diagnosis can be clinical and further investigations are not needed, unless clinically required. There is still no consensus on the etiopathology of the condition, the role of Staphylococcus aureus seems consolidated, together with the predisposing conditions of temperature and humidity of the skin folds. Design: Here we present three cases of cold abscesses of the newborn and an unprecedented pathogenetic hypothesis, based on clinical and dermoscopic findings. Results: black hair was found emerging from a cold abscess, suggesting a role of hair shedding in utero in the etiopathogenesis of this benign condition. Conclusions: The article describes three new cases of cold abscesses of the newborn, a rare and benign condition, which has to be distinguished from other similar entities. Furthermore, a new unprecedented etiopathogenetic hypothesis is proposed.

Keywords: This research received no specific grant from any funding agency in the public; commercial or not-for-profit sectors


Cold abscesses are a recently described manifestation in immunocompetent newborns. Only 17 patients are reported in the literature and in all cases, the onset of the lesions is in the first few days of life, in good general conditions, and in uncomplicated pregnancies, with excellent outcome regardless of the type of treatment. The pathogenesis is unknown although several hypotheses have been postulated. We present three new cases seen in our hospital and we suggest a new cause.

Case Series

Patient 1

The first newborn was a male, born at 40 weeks from spontaneous delivery after an uncomplicated pregnancy. He came to our attention because of the onset, on the 9th day of life, of an inguinal red nodule. On clinical examination, an erythematous nodule on the left inguinal fold was observed, together with umbilical granuloma (Figure 1). The patient was otherwise in good health, afebrile, with adequate growth. An ultrasound of the lesions was performed, showing a cutaneous-subcutaneous hypoechogenic round formation with a perimetric vascular ring, consistent with adenitis. He was then admitted to our Neonatology Unit: blood cell count and biochemical analyses resulted within normal limits. Topical antibiotic therapy was started, with mupirocin cream applied on the lesions 3 times a day. During hospitalization, the inflammatory nodule underwent spontaneous fistulation, and a cutaneous swab for bacteria from the purulent discharge was taken. After three days of treatment, it began to disappear, with dimensional reduction. No new lesions appeared. After discharge, a 20-day of life-follow up was performed, and the newborn remained healthy with normal clinical examination.


Figure 1: erythematous nodule of the left inguinal fold and umbilical granuloma.

Patient 2

The second patient was a male of 12 days of life, born at 40 weeks, after a normal pregnancy. He was visited at the Neonatal Unit because of the onset of two bilateral nodular lesions of the inguinal folds (Figure 2). An ultrasound of the region was performed, showing two superficial lesions, with underlying reactive lymph nodes. In the clinical suspicion of an infectious process, systemic antibiotic therapy was started.


Figure 2: symmetrical erythematous nodules of the inguinal folds.

On dermatological examination, he presented two inguinal symmetric nodular lesions surrounded by mild erythema. On the right lesion, minimal surface erosion was observed. The patient was in good general health, afebrile, blood tests and abdomen ultrasound were within normal limits. A swab of the purulent discharge from the right inguinal abscess was taken and resulted positive for oxacillin-susceptible S. aureus, a nasal swab resulted negative and both anal and umbilical swabs resulted positive for Morganella morganii. Since the patient was already on antibiotics, no additional therapies were prescribed, apart from a gentle washing.

On the third day of hospitalization, the right nodule spontaneously drained through the skin and a swab from the material was collected. After 7 days, the lesions underwent progressive spontaneous resolution, no further lesions appeared and the newborn was discharged in good clinical conditions.

Patient 3

Patient 3 was a female of 12 days, who came to the pediatric dermatology outpatient because of the onset, 4 days earlier, of a single swollen lesion on her right inguinal fold. After an uncomplicated course, during the last days of pregnancy, the mother was prescribed systemic antibiotic therapy because of a placental rupture. At birth, the baby was in good clinical condition and all the clinical parameters were within normal ranges. On clinical examination, she presented a nodular swollen lesion on the right inguinal fold, surrounded by slight erythema (Figure 3a). The baby was otherwise healthy, afebrile, and quiet during the examination. Surprisingly, at dermoscopic examination, a short black hair was found, emerging from the nodule and not visible to the naked eye (Figure 3b). With the help of anatomic forceps, the hair was removed and, when observed on video dermoscopy, it showed the absence of roots (Figure 3c). Videodermoscopy has performed also around the lesion and on the contralateral inguinal fold, revealing the presence of further similar sparse rootless hairs. Diagnosis of cold abscess was made and the patient was discharged without further investigations needed.