submandibular or submental regions on physical examination should prompt a careful oral and dental examination Preauricular nodes, located anterior to the ear, drain the conjunctiva and lateral eyelids These nodes enlarge with eye or conjunctival infections, of which viral infections are a prominent cause The combination of conjunctivitis and ipsilateral preauricular adenopathy is called oculoglandular syndrome, or Parinaud syndrome Infections that can present as oculoglandular syndrome include adenovirus or chlamydial conjunctivitis in neonates Rarely, catscratch disease and tularemia manifest as an oculoglandular syndrome Posterior auricular nodes, located behind the ear, and occipital nodes, found at the base of the scalp, commonly enlarge in response to scalp infections or chronic inflammation Pediculosis (lice), tinea capitis, bacterial scalp infections, and inflammation from seborrheic dermatitis are all common causes of such node enlargement in children Axillary and Epitrochlear Axillary adenopathy is commonly present with any infection or inflammation of the upper extremities Most commonly, injuries to the hand, such as occur after falling or with puncture wounds or bites, may present with concomitant axillary adenopathy as a reactive response to disruption in skin integrity Axillary adenopathy is also a common part of B henselae infection (catscratch disease), as outlined previously as a cause of cervical adenopathy Epitrochlear adenopathy is significantly less common than axillary adenopathy in children, and any epitrochlear node greater than 0.5 cm is considered enlarged Epitrochlear nodes may become inflamed after infections of the third, fourth, or fifth finger; medial portion of the hand; or ulnar portion of the forearm Most commonly, these infections are caused by pyogenic bacteria (e.g., Streptococcus pyogenes or S aureus, including MRSA), but depending on the inciting event, other pathogens may be responsible (e.g., Streptobacillus moniliformis and Spirillum minus in rat-bite fever or F tularensis in tularemia) Rare causes of both axillary and epitrochlear adenopathy include rheumatologic disease of the hand or wrist and secondary syphilis Inguinal Inguinal adenopathy most often results from lower extremity skin or soft tissue infection However, inguinal lymph nodes also drain tissues in the perianal region and unexplained adenopathy in this area should prompt examination for perirectal abscesses, fissures, or other inflammation In addition, sexually transmitted diseases such as chlamydia or gonorrhea may cause inguinal adenopathy Acute genital infection with herpes simplex virus-2 (HSV-2) often presents with tender inguinal adenopathy, occasionally as the only sign Chancroid, lymphogranuloma venereum, and syphilis are rare causes of inguinal node swelling and tenderness The presence of genital lesions, which may be either painful (as in herpes simplex virus or chancroid) or painless (as in syphilis), offers clues to these diagnoses Therefore, careful history taking and physical examination are necessary to exclude these possibilities