Now coxsackie A-9

Now coxsackie A-9; the reason I’m showing this is that this can cause rashes, maculopapular and petechial rashes, but it can also have vesicular and urticarial lesions. These frequently get misdiagnosed as contact dermatitis or poison ivy and bug bites. So this is a child who happens to have coxsackie A-9, has lesions that were quite pruritic and they look like papular urticaria. They look like bug bites. Urticaria around a central vesicular lesion. This is another enterovirus that looks like bug bites on this child, and this child as well. Also urticaria, large urticaria. This occurs in outbreaks that the first thing a lot of people think of are foods, but if you have this with fever it’s likely a viral infection, and it can be several different viruses, but particularly in the summertime, enteroviruses. This is a child that looks a little bit like having chicken pox but went on to have lesions that look like those you see in allergic purpura, and went on to have massive purpura that you see here. Looking like DIC, although she was not that sick. This for comparison is a child with scabies. If you scrape these lesions, if you scrape these other lesions you get nothing. You just get some normal epithelial cells if you do it vigorously. Whereas if you scrape poison ivy or if you scrape bug bites they are loaded with eosinophils. Here you can see the organism as well.

The last of these is hand-foot-and-mouth syndrome, and this is the most distinctive enanthem/exanthem complex. The main etiology is coxsackie A-16 but this has been seen with other enteroviruses but in outbreak circumstances it has mainly been A-16. Or when it’s described to other viruses, they don’t usually have the complete syndrome. Most recently in Hong Kong and Taiwan they had an outbreak with enterovirus 71 and they described cases of hand-foot-and-mouth. The lesions most common on hands and then the feet and buttocks. The peripheral distribution is distinct and occasionally they will go away and then come back. So you will have recurring lesions and sometimes they’ll be chronic with immune defects and sometimes with no apparent immune defects. Chronic reoccurring lesions. This is a classic case of the lesions on the heel of this child and also the buttock. The buttock lesions are usually just maculopapular and not vesicles. This is the tongue of this child’s aunt, which looks like aphthous stomatitis and this is the grandmother of that child with typical lesions on the hands. This is just to show the size of the lesions. The other day I showed you Herpes simplex lesions on the soft palate, and this is almost a 2 cm lesion in the mouth of this particular child.

Now I’m going to move on to roseola. Roseola and phantom exanthem subitum is a classic pediatric exanthem and about somewhere between 10-30% of children have roseola. It usually will occur in the first two years of life and the illness is fever for 3-5 days. The fever usually falls rapidly and then you have the appearance of the rash. But a lot of physicians just call the first rash they see in a child roseola, which you shouldn’t do. The illness is not seasonal but there have been occasional outbreaks. It has been associated with many different viruses, but recently, relatively recently, herpes virus 6 has been found to be the major cause of this but it’s not the only cause. The Japanese papers on this, the way they did their studies, it was destined to prove this was the cause. So the actual fact is there are multiple etiologies. It seems that this complex of fever and then fever dropping and rash occurring is a host phenomenon relating to multiple different virus antigens, of which the most important is probably herpesvirus 6.

This is just an example of an outbreak of roseola that occurred in Rochester New York in 1974. This is the outbreak and from a number of these they isolated echovirus 16. So showing you that, at least in outbreak circumstances, enteroviruses may play a role.

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