Viral Exanthems Flashcards
Scarlantiform vs. Morbilliform Rash
Scarlantiform Rash –> confluent, blanching erythema –> red eruption on the skin; blanching (push on it, turns white - looks like a sunburn) – Scarlet Fever, TSS, Drug eruptions, Kawasaki Disease
Morbilliform Rash
Erythematous, macular and papular rash; RED; macules are flat lesions and papules are raised lesions; discrete lesions aligned on the body –> Rubeola, Rubella, Roseola (HHV6), Erythema infectiosa (Fifths disease), Drug eruptions
Generalities of Viral Exanthems
Highly infectious disease that are transmitted via AIRBORNE droplets
Viral agents that are shed via oropharyngeal secretions and are then transmitted everywhere by kids who lick/touch everything
Primarily disease of KIDS and tend to be BENIGN and SELF-LIMITING
Not even that important to diagnose, because we just let the infection run its course!
Adults have more severe infections, and preggos can have severe infections that harm the fetus
Rubeola/Measles
Caused by a single stranded paramyxovirus
Highly contagious and spread through respiratory droplets
10-14 day incubation
Fevers, coughs, coryza (cold), conjunctivitis; following this prodrome, MORBILLIFORM RASH that typically STARTS ON THE FACE and TRUN and spreads to the LIMBS LATER, including the soles and palms of the feet
KOPLIK SPOTS –> Characteristic finding of Measles (blue-gray spots on the roof of the mouth)
Can cause pneumonitis or encephalitis in the VERY IMMUNOCOMPROMISED
90% of the cases we see now occur in kids who ARENT VACCINATED
Rubella
GERMAN MEASLES; similar
Togavirus with a ssRNA genome, commonly infects kids 5-9
Rash = diffuse, erythematous maculo-papular rash that looks just like Measles, but is “less red hot”
SIGNIFICANT LYMPHADENOPATHY
Thrombocytopenia (decreased platelets) –> PETECHIAE
Forscheimer’s Spots –> Petechiae in soft palate
Can cause ARTHRITIS of the small joints (MCP, PIP, wrists)
CONGENITAL RUBELLA if mom infected –> deafness, congenital heart disease,mental retardation
Varicella/Chickken Pox
Herpes virus family
2-3 week incubation
High fevers and a distinct rash –> lesions START as macules and progress to papules then to vesicles, which eventually burst and crust over –> ASYNCHRONOUS!! Not all the same stage
Adults/immunocompromised it is very severe and can cause systemic disease with encephalitis, pneumonitis or hepatitis
Can be complicated by SECONDARY INFECTIONS with Staph or Strep
Virus can REACTIVATE LATER IN LIFE and cause HERPES ZOSTER –> Shingles!
Small Pox
Bioterror threat!
2 week incubation before presenting with symptoms of fever, malaise, headache, vomiting
Following prodrome (2-4 days), a RASH develops with lesions starting as macules and progressing to vesicles and pustules and scabs
SYNCHRONOUS!!! ALL SAME STAGE, differs from chicken pox!
Parvovirus B19
ERYTHEMA INFECTIOSUM – FIFTH’S DISEASE
Extremely common - 80% of adults have antibodies against it, so almost everyone was exposed as a child
Presents with a prodrome period with fever, headaches, coryza and DIARRHEA
Then develop a SLAP FACE RASH (can see rash on the trunk)
Adults can develop symmetrical arthritis that may look like RA –> patient comes in with fevers and joint pain and report that their kid had URI with diarrhea and a facial rash –> Think Parvo B19!!
Can cause ANAPLASTIC ANEMIC CRISIS in patients with hemoglobinopathies
Maternal exposure can cause HYDROPS FETALIS
Roseola Infantum
XANTHUM SUBITUM
HHV6 or HHV7
Respiratory transmission, very common in children
REALLY REALLY HIGH FEVERS that can cause FEBRILE SEIZURES for 3-4 days
Once the fever breaks –> RASH WITH DISCRETE, ALMOND SHAPED, MACULAR-PAPULAR LESIONS
Rash does NOT DEVELOP until the FEVER HAS BROKEN!
Hand Foot and Mouth Disease
Most commonly caused by COXSACKIE VIRUS A16, but also other enteroviruses
Summer (dirty swimming pools)
Vesicular lesions of the HANDS, FEET and MOUTH
Mouth - erosive lesions on palate and tongue (similar to herpes) –> sore throat, pain while eating
Benign! Like all of these
Mumps
Not actually a viral exanthem
Unlike Measles, new outbreaks occur in people who HAVE been vaccinated!
Paramyxovirus, transmitted via respiratory droplets
Incubation 16-18 days
Low grade fevers and headaches and INFLAMMATION OF PAROTID GLAND (and potentially other salivary glands)
Can develop ORCHITIS in postpubertal patients, causing problems
WBCs in the CSF (51%) but only 10% develop meningoencephalitis
Scarlet Fever
Not a viral exanthem because it is NOT A VIRAL INFECTION!!
Sequelae of GROUP A STREP caused by the production of PYROGENIC EXOTOXIN
Develops 1-7 days following pharyngitis, so patient will get better then SPIKE ANOTHER FEVER and get SEVErE RASH
Confluent, blanching erythema that feels like sand paper and may desquamate
Mostly on the abdomen and in skin folds
STRAWBERRY TONGUE with circumoral pallor –> area around the mouth pale, big beefy red tongue with diffuse erythema
KAWASAKI DISEASE
Need to diagnose and treat this one to prevent long term morbidity!!! (unlike all the others)
Mucocutaneous lymph node syndrome - autoimmune acute vasculitis
Usually acute and self-limited, but 20-30% of UNTREATED PATIENTS develop CORONARY ARTERY ANEURYSMS
Patients get really sick, very high fevers, conjuctival infection with exudate, oral erythema/STRAWBERRY TONGUE, red/cracked bleeding lips, cervical LAN, polymorphous rash,e tc
TREATMENT = ASPIRIN and IVIG!!!!!
MUST treat to prevent the development of coronary artery disease and myocarditis!!!!!!
