Rashes can be described as:

their distribution on the skin size – pin-point, etc whether they are flat, raised, blistering, scaling whether they blanch on pressure itchiness painful or not associate signs and symptoms e.g. fever,

Viral exanthemata include:

infectious mononucleosis measles rubella varicella erythema infectiosum roseola Dengue fever a number of other mild viral illnesses can cause a rash

Bacterial exanthemata include:

streptococcal - scarlet fever meningococcal staphylococcal - toxic shock, scalded skin syndrome, scarlet fever Lyme disease Syphilis

Non-infective exanthemata include:

systemic lupus erythematosus erythema multiforme, which may also be related to an underlying infection, drugs

Diseases Rashes Other features1. Measles/Ruboela Typically begins at the

hairline and spreads caudally over the next 3 days as the prodromal symptoms resolve.

Rash lasts 4-6 days and then fades from the head downward.

The rash is a maculopapular erythematous rash

Desquamation may be present but is generally not severe.

Complete recovery from the

10 days after the initial exposure to the virus, the classic viral prodrome occurs; fever, non productive cough, coryza, conjunctivitis, sometimes malaise, myalgias, photophobia, and periorbital edema.Within 2-3 days, the pathognomonic Koplik spots typically arise on the buccal, gingival, and labial mucosae

illness generally occurs within 7-10 days from the onset of the rash

2. Rubella/German measles

rash develops within 1-5 days of symptom onset, starting on the face and forehead and spreading caudally to involve the trunk and extremities

The rash consists of pink macules and papules, which may become confluent, resulting in a scarlatiniform eruption.

The rash tends to clear in the same order as it appeared.

The rash may be pruritic, but it usually resolves within 3 days without residua

Incubation period is 14-23 days. Prodrome is characterized by fever, malaise, anorexia, headache, mild conjunctivitis, rhinorrhea.Lymphadenopathy may be present, particularly in the posterior auricular, posterior cervical and suboccipital chains. Petechiae of soft palate (Forchheimer sign) may be present.

3. Chickenpox4. Scarlet fever 5. Fifth Disease/Erythema

Infectiosum6. Dengue Fever7. Infectious

Mononucleosis

Image in a 4-year-old girl with a 4-day history of low-grade fever, symptoms of an upper respiratory tract infection, and rash. Diagnosis = rubella.

A characteristic red, blotchy rash appears around the third day of illness, beginning on the face and becoming generalized. The skin rash of measles is an allergic response to virus products in the body rather than direct viral multiplication in skin cells.

Koplick spots are a characteristic of measles used in diagnosis. They appear opposite the molars as red spots with blue white centers.