The informal term “railroad track ears” describes a specific, visible characteristic of the ear present from birth. This feature appears as small depressions, folds, or dimples located near the front of the ear, often where the cartilage meets the face. Medically, this congenital feature is known as a preauricular pit or sinus. Understanding the medical context is important for identifying potential health implications and knowing when medical attention is necessary.
Understanding the Informal Term
The appearance nicknamed “railroad track ears” is medically known as a preauricular pit or sinus. This is a small, shallow indentation or hole typically found on the skin directly in front of the upper outer ear, near the ascending helix. The opening often resembles a tiny pinhole or a slight dimpling, and it is a common congenital malformation. The pit is the visible manifestation, representing the external opening of a narrow, blind-ending tract—the preauricular sinus—whose length and complexity vary significantly.
The Underlying Anatomical Cause
A preauricular pit or sinus is classified as a congenital malformation, developing before birth during the early stages of fetal growth. The external ear, or auricle, begins to form around the sixth week of gestation from six small mounds of tissue known as the hillocks of His. These hillocks arise from the first and second branchial arches, which contribute to the formation of the face and neck. Complete development requires the seamless fusion of these six hillocks into the final shape of the auricle.
The preauricular feature results from an incomplete fusion of these embryonic hillocks. Instead of the tissue closing completely, a small fold of ectoderm—the outermost layer of tissue—becomes trapped beneath the surface. This trapped tissue forms the epithelial-lined tract, or sinus, which terminates in the small, visible pit.
Potential Health Risks and Complications
For many people, a preauricular pit remains entirely asymptomatic and causes no health concerns. The primary complication requiring medical attention is the risk of infection, especially when the pit extends into a deeper sinus tract. This tract is lined with skin cells that continuously shed debris and keratin. This accumulation, combined with secretions and external bacteria, creates a confined environment conducive to bacterial growth.
If the opening of the pit seals shut, the debris becomes trapped, leading to inflammation and bacterial colonization. The resulting infection is characterized by painful swelling, redness (erythema), and warmth around the ear, known as cellulitis. If the infection progresses, it can form a subcutaneous cyst or an abscess, which is a localized pocket of pus that requires draining. Recurrent infections are a concern, as each episode causes scarring and can complicate future treatment.
Diagnosis and Treatment Options
Diagnosis of a preauricular pit is straightforward, involving visual inspection during a routine physical examination. Because the condition is congenital, a healthcare provider easily identifies the small opening near the ear at birth. If the preauricular feature is present alongside other facial or ear abnormalities, specialized imaging like an audiogram or a kidney ultrasound may be recommended to rule out rare associated genetic syndromes. For most patients, however, the pit occurs in isolation and has no connection to hearing loss or kidney issues.
Management is determined by whether the pit is symptomatic or asymptomatic. An asymptomatic pit that has never been infected requires no treatment, though monitoring for signs of trouble is advisable. If an acute infection occurs, the initial approach involves a course of oral antibiotics to clear the bacterial infection and reduce inflammation.
If an abscess forms, a medical professional may perform a needle aspiration to drain the pus. For patients experiencing recurrent infections or chronic discharge, the definitive treatment is surgical excision. Surgery removes the entire epithelial-lined sinus tract to prevent future recurrences.