Please help with this medical case...?

Y.a an 8 month old male, was admitted for the first time on July 8, 2007.

Chief complaint: rashes

History of present illness:
Condition started 3 days prior to admission as sudden onset of fever, (documented as temperature of 39 celsius). Patient was given paracetamol (naprex 100mg.ml) drops 1.2ml every 4 hours which afforded temporary relief. Patient had minimal rhinorrhea and was noted to have decrease in appetite. Parents did not seek consult because of financial difficulty. The morning prior to admission, temperature was noted to be 37.5celsius and parents noted the appearance of rashes.

(+) soft watery stool 1-2 episodes/day
(+) vomiting

Past history:
Prenatal: mother G2P2002. had prenatal check up at the health center. No maternal illness incurred during the entire gestation. Took multivitamins regularly.
Natal: patient was delivered at home assised by a midwife. Good spontaneous crying was noted right after delivery. Birth rank is 2/2
Postnatal: patient was breastfed since birth up to 6 months old. Solid food was introduced at 5 moths old. Developmental milestones 鈥?unremarkable.
Immunization status:complete primary immunization done at the health center.

P.E: examined a conscious, irritable, afebrile patient with the following vital signs
HR: 100/min RR: 25/min Temp: 37celsius weight: 8 kg
Skin: (+)discrete, small slightly raised pink lesions in the trunk. (-) jaundice
HEENT: (-) eye discharge, (+) watery nasal discharge, (-) tonsillopharyngal congestion
Neck: supple
Chest and lungs: equal chest expansion, clear breath sounds
CVS: regular rate and rhythm
Abdomen: flat, soft, normoactive bowel sounds
Genitourinary: grossly male, descended testes
Extremeties: no limitation of movement, strong pulses, capillary refill time(CRT) < 2 sec

Questions:
1. what is your impression of the case?
2. what is the primary causative agent of this particular disease entity?
3. what is its incubation period?
4. what may be noted during the prodromal period of your primary impression?
5. what is the typical pattern of fever in this disease entity?
6. what is a likely differential diagosis of this disease entity?
7. what would be the likely presentation of your differential diagnosis ( rash in relation to fever)?
8. Is this preventable by vaccine?

1. the condition is generally good, disease controlled by medications
2. it is viral disease, watery nasal discharge
4. fever of sudden onset
5. sudden
6. other viral infections with rash & gastroentritis
7. in chicken pox rash proceeded by fever by 1 day. in measles by 4 days, ...etc
8. no ( he completed his vaccination yet caught infection)

I am sorely disappointed if this is a medical student actually posting for help on here regarding a case!