A newborn with eyelid swelling, chemosis, and pseudomembrane formation most likely has which condition?

The presence of eyelid swelling, chemosis (swelling of the conjunctiva), and pseudomembrane formation in a newborn is highly indicative of chlamydial conjunctivitis. This condition typically occurs following exposure to Chlamydia trachomatis during delivery, especially in cases of maternal chlamydial infection.

The swelling and chemosis are due to the inflammatory response of the conjunctiva to the infection, while pseudomembrane formation is characterized by the presence of a fibrinous exudate on the conjunctival surface, which is a hallmark of severe cases. Timely recognition and treatment are critical, as chlamydial conjunctivitis can lead to complications if not adequately addressed.

In contrast, other conditions like herpes simplex keratoconjunctivitis often present with vesicular lesions, and gonococcal conjunctivitis typically features more purulent discharge and a quicker onset after birth. Newborn glaucoma is related to increased intraocular pressure and typically does not present with these specific conjunctival signs. Therefore, the symptoms described align most closely with chlamydial conjunctivitis, making it the most likely diagnosis.