Isolated unilateral hypoglossal nerve palsy from suppurative retropharyngeal lymphadenitis in an infant.

Retropharyngeal infections (RPIs) are uncommon in young infants and are difficult to diagnose due to their non-classical presentation. RPI can occasionally be complicated with multiple cranial nerve palsies but rarely in isolation. Isolated hypoglossal nerve palsy (HNP) due to RPI has been described in the literature but mostly in older children and adults. Assessment for hypoglossal nerve function is challenging in a young infant because the conventional signs of hypoglossal nerve dysfunction are difficult to elicit in this age group. Early recognition and treatment of RPI are associated with good HNP recovery. We present a case of a young infant with tongue deviation and difficulty with feeding attributed to an isolated HNP caused by suppurative retropharyngeal lymphadenitis. The infant underwent incision and drainage with complete recovery of the tongue function after 8 weeks.