Viral infections of the throat are common and, although many practitioners are under pressure from the patient to give antibiotics, the vast majority are usually self-limiting, settling with bed rest, analgesia and encouraging fluid intake. Fungal infections, usually candidiasis, are uncommon and may indicate an immunocompromised patient or undiagnosed diabetes.

Tonsillitis

Tonsillitis, with a good history of pyrexia, dysphagia, lymphadenopathy and severe malaise is usually bacterial with β-haemolytic streptococcus the commonest organism.

This is an ophthalmic emergency. In this type of glaucoma there is a sudden rise in intraocular pressure to levels greater than 50 mmHg. This occurs due to reduced aqueous drainage as a result of the ageing lens pushing the iris forward against the trabecular meshwork. People most at risk of developing AACG are those with shallow anterior chambers such as hypermetropes and women. The attack is more likely to occur under reduced light conditions when the pupil is dilated.

AACG causes sudden onset of a red painful eye and blurred vision. Patients become unwell with nausea and vomiting and complain of headache and severe ocular pain. The eye is injected, tender and feels hard. The cornea is hazy and the pupil is semi-dilated. Table 20.8 shows the differential diagnosis of the acute red eye.

Prompt treatment is required to preserve sight and includes i.v. acetazolamide 500 mg (provided there are no contraindications) to reduce IOP, and instillation of pilocarpine 4% drops to constrict the pupil to improve aqueous outflow and prevent iris adhesion to the trabecular meshwork. Other topical drops such as beta-blockers and prostaglandin analogues can also be instilled if available, provided there are no contraindications. Analgesia and antiemetics are given as required.

These patients must be referred to an ophthalmologist immediately so that reduction in IOP can be monitored and other agents such as oral glycerol or i.v. mannitol can be administered to non-responding patients. Definitive treatment involves making a hole in the periphery of the iris of both eyes either by laser or surgically.

Varicella zoster virus (VZV) causes the common childhood infection called chickenpox. It also causes herpes zoster.

Herpes zoster (shingles)

‘Shingles’ results from a reactivation of the VZV. It may be preceded by a prodromal phase of tingling or pain, which is then followed by a painful and tender blistering eruption in a dermatomal distribution. The blisters occur in crops, may become pustular and then crust over. The rash lasts 2-4 weeks and is usually more severe in the elderly. Occasionally more than one dermatome is involved.
Complications of shingles include severe, persistent pain (post-herpetic neuralgia), ocular disease (if ophthalmic nerve involved) and rarely motor neuropathy.

Treatment

Herpes zoster requires adequate analgesia and antibiotics (if secondary bacterial infection is present). Valaciclovir 1 g or famciclovir 500 mg three times daily for 7 days is used, or oral aciclovir 800 mg, five times daily for 7 days helps shorten the attack if given early in the illness. High-dose intravenous aciclovir is needed for immunosuppressed patients. It remains unclear how useful aciclovir therapy is in preventing prolonged post-herpetic neuralgia.