Mrs. Samson brings her 3-month-old baby boy to see you because she’s worried about a “hole” in front of her baby’s left ear. She’s concerned and wonders whether further investigations are necessary. When you examine the baby, you identify a preauricular pit.
You vaguely recall that this may be associated with kidney anomalies and hearing impairment. What should you do?
Isolated preauricular ear pits and skin tags are minor anomalies that are not infrequently encountered in daily practice. The incidence is from 5-10/1,000 live births.1 Is there an increase in renal anomalies in these children? Kohelet and Arbel found that 6/70 infants with isolated preauriuclar skin tags had a urinary tract abnormality (5 hydronephrosis, 1 horseshoe kidney) compared with 0/69 in a control group undergoing ultrasound for persistent vomiting/cyanotic spells. None of the infants required surgery for their reflux and hydronephrosis although we’re not told for how long they were followed.2
Firat identified 36 school-aged children with isolated ear pits/skin tags (29 skin tags, 7 ear pits) out of 13,740 children who were undergoing a general health screening. These kids were followed up with urinalysis, renal ultrasound and an otoacoustic emissions test. One child out of the 36 had hydronephrosis and reflux. The control group of 91 kids had 3 with renal anomalies (1 unilateral renal dysgenesis, 2 with U-P junction obstruction). So, there was no significant difference between the groups (p = 0.89). Similarly, there was no difference between the groups in hearing impairment (p = 0.45). These authors concluded that routine renal ultrasound or hearing tests weren’t indicated in children with isolated ear pits or skin tags.
Deshpande and Watson came to the same conclusion from their study of 13,136 infants, of whom 96 were found to have minor ear anomalies such as pits and tags.3 Of these 96 infants, all of whom underwent renal ultrasounds, only 1 infant had pyelectasis secondary to U-P junction obstruction and this resolved spontaneously by 14 months of age.
Bottom line: there’s no need to do a renal ultrasound in an infant with a minor anomaly such as a preauricular pit or skin tag. This is especially true when almost all pregnant women have screening antenatal ultrasounds. I must emphasize that we’re excluding ear anomalies associated with syndromes such as CHARGE, BOR (Branchio-Oto-Renal), Goldenhar or Treacher Collins and others in which there’s a much higher incidence of hearing loss and renal abnormalities.
Should you do a hearing assessment in infants with these minor anomalies? A recent study out of Israel suggests that the answer is yes. Roth and co-authors asked the question, “Is there an increased incidence of hearing impairment in infants with preauricular pits or skin tags?”4 In their study over a 7.5-year period, 68,484 infants had a screening hearing test (universal newborn hearing screening tests were in place in the study hospital). Six-hundred and thirty-seven of the infants had preauricular skin tags or ear pits. The authors divided these infants into three groups depending on their risk for hearing impairment. The groups were low risk, high risk and very high risk. The low-risk group had no risk factors other than the ear pits/tags. The high-risk group had risk factors such as a family history of sensori-neural hearing loss, in-utero infection, hyperbilirubinemia, etc. The very high-risk group had major ear anomalies or anomalies associated with syndromes such as Goldenhar, CHARGE, etc. Excluding the very high-risk group with known syndromes involving hearing loss, the interesting finding was that the OR (odds ratio) for hearing impairment in the “low-risk” group with preauricular pits/skin tags was 6.7, and in the “high-risk” group 4.1. I agree with the authors’ conclusion that infants with these minor ear anomalies should have a screening hearing test where universal newborn screening is not in place.
So, I’d advise Mrs. Samson that an ultrasound is not necessary but, if the baby has not already been screened, I’d do a hearing test (otoacoustic emissions screening test with auditory brainstem response [ABR]) as necessary and follow-up if abnormal.