Rashes in children

Complementing our current series on infectious diseases in children, Dr Mike Wyndham offers a selection of images of rashes in children, which aims to help distinguish between the appearance of once-common childhood illnesses. For further detail on the management of these conditions, please refer to previous articles in the series, available online at practicenurse.co.uk, and look out for forthcoming articles

CHICKENPOX

Chickenpox is caused by the herpes varicella-zoster virus and usually affects children under the age of 10 years. However, evidence suggests that it is now beginning to affect older people more commonly. This has implications for the pregnant woman with the potential for a foetus suffering from congenital chickenpox. It is an airborne infection, spread by respiratory secretions or by direct contact, and it has an incubation period of 10-21 days. The rash appears in 4 stages: macule, papule, vesicle and then finally pustule. There is a phenomenon called cropping where lesions are present at different stages. Symptoms vary, with some suffering a great deal of itching while others less so. The application of calamine is helpful. Once the lesions have scabbed over the sufferer is no longer contagious. Adults with chickenpox are at risk of pneumonitis and should be offered antiviral treatment such as acyclovir within 24 hours of the rash appearing.

ROSEOLA INFANTUM

Roseola infantum is caused by human herpesvirus 6, and as it name suggests, it mainly affects children under 1 year. The child starts with a high temperature (up to 40 degrees) which lasts for 3 days with few other symptoms. At this point, the fever ceases and within 24 hours a macular rash will appear as shown in the image. At this point the child is already returning to normal. This illness highlights an important lesson for the clinician. When encountering a young, sick child with a high temperature, it is tempting to find a reason to prescribe antibiotics, for example, 'the ear was looking a little pink'. If this is done in this case, the rash will be considered to be due to antibiotics and that individual will be wrongly denied them lifelong.

MEASLES

The re-emergence of this illness gives a lesson to the population at large, about the impact of misinformation. Measles is a seriously miserable illness with significant morbidity, even mortality, and people did not realise the potential issues when they failed to immunise their children.

The illness commences with a fever, which may last up to a week. (I was taught that if you plot the temperatures on a graph it creates an 'M' shape). Other symptoms during this period include the triad of cough, coryza and conjunctivitis. During the early stage of the illness, koplik spots, which have the appearance of salt grains, appear on the buccal mucosa. One or two days after this, a macular rash appears firstly on the face and neck, and later extending to the trunk and limbs. Complications include otitis media, pneumonia, diarrhoea, stomatitis and keratitis. The development of encephalitis, while rare, may cause death. Rarely, subacute sclerosing panenecaphalitis may occur, many years after the original infection.

HAND FOOT & MOUTH

This condition is caused by coxsackie virus which is a subgroup of the enteroviruses. Naming the illness can cause some alarm to patients and their family as they may link it to the cattle disease. They should be reassured that there is no connection. The incubation period is around 3-5 days. The virus may be excreted in the stools for some weeks after the infection. The infection commonly occurs in outbreaks in the summer or autumn, mostly affecting children but it may affect adults too. Symptoms include a fever and the development of vesicles which are distributed as described by the name. However, just to complicate matters, the lesions may occur anywhere on the body! In the mouth, the vesicles covert to shallow ulcers. Treatment should be symptomatic, and the infection will resolve in a few days.

ERYTHEMA INFECTIOSUM

Erythema infectiosum, otherwise known as slapped-check virus or fifth disease, is caused by human parvovirus B19. It tends to occur in outbreaks about every 3-4 years. Frequently there are no prior symptoms to the appearance of bright red cheeks but some patients may develop symptoms such as sore throat, fever and headache, and these are much more likely to occur in an adult. After a few days a maculo-papular rash develops on the trunk and limbs, which converts to the appearance of a lace cloth, but which ultimately disappears. Overall, the child is not unwell. Once the rash appears, infectivity has ceased. If an adult is affected a symmetrical arthralgia may develop. This may last for months, and is more likely to occur in women. It is important to consider this diagnosis in women with new onset joint pain. Infection in pregnancy may lead to hydrops foetalis or even foetal death, but there is no evidence that it causes congenital malformations. Patients with sickle cell disease, hereditary spherocytosis and beta-thalassaemia may suffer aplastic crises.

RUBELLA

Rubella has disappeared from the general population as a result, first, of the single rubella vaccination and then MMR. Up until recently, we would only have expected to see rubella in non-immunised people who have migrated to the UK. Will a fall in those numbers immunised against MMR cause a rise in the number of cases of rubella? This author expects so. The illness is mild to non-existent in children affected by the illness. Presentation may just be with rash, which is macular extending from the face and neck to the trunk. The clinician should check for suboccipital glands to confirm the diagnosis. No specific treatment is required. If an adult develops the condition, they feel unwell and may develop headache, sore throat, joint pain, conjunctivitis along with the rash and lymphadenopathy. Rubella occurring in pregnancy causes a triad of cataracts, deafness and congenital heart disease.