Pharyngoconjunctival fever (PCF) is a clinical syndrome caused by adenoviruses. PCF may occur in unrelated incidents, or as an epidemic. The main features are conjunctivitis, pharyngitis, and fever. It is highly contagious.
Most cases of conjunctivitis are caused by viruses, of which the most common microorganism is adenovirus  . Viral conjunctivitis is often misdiagnosed as having a bacterial etiology, as viral conjunctivitis presents similarly to other types of conjunctivitis .
Pharyngoconjunctival fever (PCF) is a specific syndrome commonly caused by certain serotypes of the human adenovirus . PCF can either occur sporadically or as an outbreak, however, it is more common in warm weather. Populations most susceptible to outbreaks are children in institutions such as schools, and people sharing living quarters. Most outbreaks originate from contaminated water bodies such as public swimming pools .
PCF and epidemic keratoconjunctivitis (EKC) are the more frequent syndromic manifestations of adenoviral infection of the eye. PCF is typically less severe than EKC . The incubation period ranges from 5 days to almost 2 weeks, after which patients experience fever that usually resolves over the period of 10 days. There may be a history of exposure to individuals with conjunctivitis or pharyngitis, as infected individuals are highly contagious in the first few days of symptomatic infection. The infection is acute, self-limiting, and is more severe in patients with low immunity. Superimposed bacterial infection is possible.
PCF initially affects one eye, becoming bilateral as the infection progresses. Ocular manifestations include pronounced conjunctivitis. Common complaints are redness, burning, tearing, itching, and photophobia. In addition, there may be a watery discharge, edema, bruising, and tenderness of the eyelids.The appearance of the eye may resemble that of traumatic injury. The virus may occasionally cause the formation of a pseudomembrane (an even rarer occurrence in other types of conjunctivitis) which may be accompanied by a mucopurulent discharge, mostly consisting of mononuclear white blood cells. Subepithelial infiltrates (SEIs), white lesions on the cornea, are a consequence of the disease and may remain for months after the infection has cleared. This leads to possible visual disturbances, including decreased visual acuity.
Systemic symptoms include high-grade fever and tender or non-tender lymphadenopathy (approximately half of known cases), particularly in the cervical and preauricular regions . Other non-specific features include general malaise and muscle pain.
The diagnosis of pharyngoconjunctival fever is clinical . Possible studies carried out entail viral culture, adenovirus-specific antibody titers, polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and immunochromatography. Viral cultures may only be beneficial within the first 10 days of infection. Antibodies against the virus are gauged via complement fixation, where blood samples are drawn soon after symptoms appear, and then after 2 to 3 weeks later. An increase in antibodies in the second sample of at least four times the original sample is indicative of recent adenoviral infection. Typically, laboratory tests take about a week to yield results. Electron microscopy may also be utilized.