there are many many causes for a rash but when one shows up in school teachers assume the worst. they are worried about measles chicken pox lyme disease scarlet fever fifth disease impetigo herpes simplex/zoster hand/foot/mouth disease mrsa or roseola just to name a few. it is this fear of imminent contagiousness that leads to the child’s exclusion from school. sometimes the skin eruption is due to allergies such as hives or just a worsening dry-skin condition like eczema (atopic dermatitis). even a cold virus (whether it’s in a cold that’s at the contagious stage or not) can cause a rash. fortunately for all of us most rashes that children get are not serious or contagious. i have seen children excluded for insect bites hives sunburns poison oak/ivy eczema and even zits. teachers are not dermatologists so they are not going to make the diagnosis. the school is just going to exclude the child and require a clearance note before the child can return. i had a child excluded this week with poison oak. poison oak is not contagious but at least half of the people i encounter think that it is. the oleoresin of the rhus plant is definitely contagious but once this oil has been washed off of the contaminated skin clothing and other objects it can no longer cause trouble. when people see this ugly rash oozing they assume the drainage is the “poison. ” this is not true. once the person takes a good shower and changes their clothes they do not need to be treated like they have leprosy. high school wrestlers tend to get a variety of skin infections from those contaminated mats. i see common warts molluscum (another wart-like skin lesion) impetigo (a staph or strep skin infection) and more recently mrsa (a potentially serious drug-resistant staph infection). of course the wrestlers are also excluded from participation because of eczema mosquito bites and other non-contagious skin issues. referees and coaches are getting better in recognizing skin problems i must say. “it’s not measles. ” i must say this statement a dozen times a week contradicting home diagnoses made by day-care providers and grandmothers. measles is relatively rare in the united states now. personally i have not seen a case in over 20 years thanks to the effectiveness of vaccinations. a few hundred to a few thousand cases still occur in the u. s. depending on the year in unvaccinated individuals. mosquito and flea bites can mimic early chicken pox lesions but only for a short while. chicken pox (varicella) looks like a “dew drop sitting on a rose petal. ” it is a tiny blister on a red base which turns into a scab followed by a tiny crater (pox) in a day or so. although varicella-immunized children can get a mild case it really does look different than mosquito bites. chicken pox is caused by the herpes virus so re-exposure to this disease later in life can cause a reactivation of the virus resulting in herpes zoster also known as shingles. warts are contagious but not very much. to exclude a child from school because of warts is really unnecessary. it can take a month or more to effectively treat a case of stubborn warts freezing them with liquid nitrogen or chemically burning them with various acids. high school wrestlers with warts can wrestle as long as they are covered by clothing or a bandage but many are excluded from participation by an eagle-eyed referee.
what can cause a skin rash?