Measles

Introduction 

Measles is an acute, highly infectious disease characterized by fever, respiratory symptoms, Koplik spots and a maculopapular rash. 

-Measles virus is a highly contagious, spherical, single-stranded, enveloped RNA virus that is a member of the Paramyxoviridae family.

-The virus gains access to the human body via the respiratory tract and is transmitted primarily by respiratory droplets

-Measles is endemic throughout the world.

Symptoms & Signs 

Incubation period: The incubation period for measles is 10 days to fever onset and 14 days to rash onset. 

Prodromal Phase: Cough, Coryza, Conjunctivitis, high-grade fever. Coryza consists of nasal obstruction, sneezing, and sore throat resembling upper respiratory infections. 

Koplik spots

-Pathognomonic of measles

-typically occur 2 days before the rash and only last 12 to 72 hours. 

-they appear as small, irregular and red with whitish center on the palatal or buccal mucosa opposite the molars or on vaginal membranes – ‘grains of sand’ or ‘table salt crystals’ 

Rash: Maculopapular rash progressing in  “downward and outward” fashion; appears 3 – 4 days after onset of prodrome, begins on the face and behind the ears; then spreads to the trunk and extremities, including the palms and soles

-Patients are contagious during the prodromal phase (2–4 days) and the first 2–5 days of rash In the hospital setting, patients with measles should be placed under air-borne precautions.

Diagnosis 

-Diagnosis is made based on clinical features 

-Labs: Leukopenia, thrombocytopenia, proteinuria  

-A positive serum immunoglobulin (Ig) M antibody for measles confirms the diagnosis. Treatment 

-Antipyretics, fluid resuscitation 

-Vitamin A treatment to reduce morbidity and mortality 

-Limited use of antivirals like ribavirin 

-Serious complications include otitis media, encephalitis, pneumonia, and bleeding disorders. 

Infection confers lifelong immunity.

Prevention

Vaccination 

Two doses of vaccine are estimated to be 97% protective. 

Children: Measles, mumps, and rubella vaccinations should be given as MMR or MMRV at 12–15 months and again at 4–6 years of age. 

Adults: Adults born in 1957 or later should have at least one dose of MMR vaccine 

Contraindications: Vaccine contraindicated in pregnant women, women intending to become pregnant within the next 28 days, immunocompromised persons, and persons with an anaphylactic reaction to a prior dose or vaccine components like neomycin, gelatin, and in children receiving high-dose corticosteroid therapy 



Infectious Mononucleosis – Mono

Introduction

Infectious mononucleosis is a clinical syndrome caused by  Epstein-Barr virus, but other viruses can also cause similar symptoms.

-The virus is transmitted through bodily fluids such as saliva (‘kissing disease) and sputum 

-It occurs mainly in adolescents and young adults 

Symptoms & Signs 

-It is characterized by a triad of fever, pharyngitis, and lymphadenopathy.

-Other symptoms include malaise, anorexia, myalgia, transient bilateral upper lid edema (Hoagland sign), radiation of pain to the left shoulder (Kehr’s sign) and splenomegaly 

-Highly suggestive findings: Epitrochlear adenopathy, posterior cervical lymphadenopathy 

-A morbilliform or papular rash, usually on the arms or trunk 

Diagnosis 

Antibody Tests: The most commonly performed diagnostic test is a rapid heterophile antibody test (Monospot test) 

White blood cell counts: Increased number of circulating white blood cells with a predominance of lymphocytes

Other labs: Elevated aminotransferases 

Treatment 

-The typical illness is self-limited and most symptoms resolve within 2–4 weeks.

-Symptomatic treatment: Antipyretics, analgesics, oral fluids, rest 

-Misdiagnosing it  as Strep throat and treating with amoxicillin can result in patient getting a rash and you getting a disappointed patient and their parents 

-Upper airway obstruction and severe hematologic complications: Consider corticosteroids 

-Potential complications: Splenic rupture, airway obstruction, pneumonitis, hemolytic anemia, thrombocytopenia, aplastic anemia, encephalitis, optic neuritis, meningitis, Guillain-Barré syndrome

– Patients should avoid contact sports and heavy lifting for 4 weeks due to the risk of splenic rupture



Herpes Zoster (Shingles)

Introduction

-Herpes zoster results from reactivation of latent varicella-zoster virus infection within the sensory ganglia 

-It is usually characterized by a painful, unilateral vesicular eruption in a dermatomal distribution 

-It is usually occurs among adults, but rarely occurs in other age groups also. 

Symptoms & Signs 

-Most commonly involved sites of herpes zoster: trigeminal, thoracic and lumbar 

-It is usually confined to a single dermatome on one side and associated with burning pain in the affected area, fever, malaise, headache

-The rash starts as grouped vesicles and later become pustular and crusty. 

Herpes zoster ophthalmicus: Lesions on tip of nose, inner corner of eye and root and side of nose (Hutchinson sign) 

Herpes zoster oticus (Ramsay Hunt syndrome): vesicles in the ear canal, hearing loss, vertigo, tinnitus, Bell palsy; due to reactivation of VZV within the geniculate ganglion. 

-The lesions are considered infectious until they dry and crust over 

Diagnosis 

-Diagnosis is based on the clinical presentation

Treatment 

Antiviral agents: Acyclovir, valacyclovir, famciclovir, beneficial if started within 72 hours after the eruption of the rash 

Anterior uveitis: topical steroids, cycloplegics 

Corticosteroids do not prevent the development of postherpetic neuralgia

Prevention 

-Two shingles vaccines (Zostavax and Shingrix) are available for adults who have had chickenpox. 

-Shingrix is preferred over Zostavax.

-Shingrix is approved and recommended for people age 50 and older, including those who’ve previously received Zostavax. 

-Zostavax isn’t recommended until age 60. 

-Shingles can spread through direct contact with herpes zoster lesions 

-Patients should avoid contact with pregnant women who have never had chickenpox or varicella vaccine, immune deficiencies, and premature infants. 

Q.What is the most common complication of zoster in elderly adults? Postherpetic neuralgia 

Q. What is the most common cause of acute retinal necrosis? Herpes zoster virus



Chickenpox by Dr.Paul Kattupalli

Introduction

-Chickenpox is an infection caused by the varicella-zoster virus. 

-VZV is a double-stranded, linear DNA virus 

-VZV infection causes two clinically distinct forms of disease: varicella (chickenpox) and herpes zoster (shingles).

-It is highly contagious, spreads readily by airborne droplets and by direct contact. 

Symptoms & Signs 

-Varicella most frequently occurs in children <10 years old but may occur at any age. 

-Varicella usually is a mild, self-limited illness in healthy children. 

-Fever, headache, malaise, papules, vesicles, crusts and scabs 

-It appears on the back of the head and ears, and then spreads centrifugally to the face, neck, trunk, and proximal extremities. 

-Vesicles are described as ‘dew drops on a rose petal’

Diagnosis 

-Diagnosis is clinically made based on history and physical examination

-Tzanck smear of the vesicle: Giant cells with inclusion bodies

-Histology: “Balloon degeneration” of cells with basophilic nuclei 

Treatment 

-For healthy children  ≤12 years, varicella is mostly self-limited; no antiviral therapy

-Immunosuppressed children and adults: antiviral therapy 

-Do not give aspirin because it is associated with the onset of Reye syndrome in the setting of a viral infection 

-Breastfeeding is encouraged in infants exposed to or infected with varicella. 

Prevention 

-A live attenuated varicella vaccine is available. 

-It is administered subcutaneously

-It is given in two doses; first dose at age 12 through 15 months, the second dose at age 4 through 6 years