ملخص

Infectious mononucleosis (IM) and Epstein-Barr virus (EBV)

The virus is acquired from asymptomatic excreters via saliva, by droplet infection, or by kissing.
Whereas ~90% of cases of IM are due to EBV,
5–10% of cases are due to Cytomegalovirus (CMV).
CMV is the most common cause of heterophile-negative mononucleosis.
Clinical features
fever, headache and malaise, succeeded with severe pharyngitis, , and non-tender cervical lymphadenopathy.
periorbital oedema, splenomegaly, rashes may occur.

In most cases fever resolves over 2 weeks, and other abnormalities settle over a further few weeks.
EBV may present with jaundice, pyrexia of unknown origin
Death is rare but can occur due to
1. Respiratory obstruction.
2. Haemorrhage
3. Encephalitis.

In children under 10 years the illness is

mild and short-lived, but in adults over
30 years of age it can be severe and
prolonged.


Investigations
Atypical lymphocytes are common in
EBVinfection
A 'heterophile' antibody is present during the acute illness detected by the
Paul-Bunnell or the slide test
'Monospot'.
Specific EBV serology (immunofluorescence) can be used to confirm the diagnosis if necessary.
CNS infections may be diagnosed by detection of viral DNA in cerebrospinal fluid.
Management
1-If a throat culture yields
aβ-haemolytic streptococcus, a course of penicillin should be prescribed
When pharyngeal oedema is severe, a short course of corticosteroids
Antivirals are not sufficiently active against EBV.

Shingles (herpes zoster)

Varicella zoster virus ,(VZV) persists in latent form in the dorsal root ganglion of sensory nerves and can reactivate in later life as a localised rash or with other clinical manifestations.
Commonly seen in the elderly, shingles
may also present in younger patients
with immune deficiency.
Chickenpox may be contracted from
acase of shingles but not vice versa.


Clinical features
Burning discomfort occurs in the affected dermatome, where discrete vesicles appear
, associated with a brief viraemia and can produce distant satellite 'chickenpox' lesions.
Severe disease, a prolonged duration of rash, multiple dermatomal involvement or recurrence suggests underlying immune deficiency.
Thoracic dermatomes are most
Commonly involved .
Ophthalmic division of the
trigeminal nerve is also frequently
affected;vesicles may appear on the
cornea and lead to ulceration,and
can lead to blindness.

Bowel and bladder dysfunction

occur with sacral nerve root
involvement.
The virus occasionally causes
myelitis or encephalitis.

Post-herpetic neuralgia

Postherpetic neuralgia arises in approximately 20% of patients .
. It is more common with advanced age.


Ramsay Hunt syndrome
Involvement of the Geniculate ganglion causes facial palsy, loss of taste and buccal ulceration, plus a rash in the external auditory canal.

Management and prevention

Aciclovir has been shown to reduce both early- and late-onset pain.
valaciclovir and famciclovir . are with superior efficacy and good safety and tolerability.
Post-herpetic neuralgia requires aggressive analgesia, along with amitriptyline or gabapentin. Capsaicin cream may be helpful.
controversial, corticosteroids reduce post-herpetic neuralgia
. Aciclovir is therefore cost-effective in shingles but not chickenpox.

Human VZ immunoglobulin (VZIG) is used to :

attenuate infection in people who have had significant contact with VZV
are susceptible to infection
are at risk of severe disease
Newborn whose mother develops chickenpox no more than 5 days before delivery or 2 days after delivery.

Susceptible contacts who develop severe chickenpox after receiving VZIG should be treated with aciclovir.

VZV vaccine ,. Is a live, attenuated

should not be given to individuals who have
A weakened immune system
Individuals with active, untreated tuberculosis.
Pregnant women should not receive this vaccine.