For their first morning, Doctors Aurélie Acher from Caen, Jean-Paul Claudel from Tours and Thomas Hubiche from Fréjus chose to attend the seminar on neonatal dermatology, a fascinating subject, in which knowledge is developing very quickly.
Cutaneous rashes in newborns
Professor Peter Hoegert presented the various causes of exanthema in newborns.
Infectious causes play a primary role. The clinical presentation is seldom specific to an infectious agent; likewise, an infectious agent can produce different clinical signs. For example, blueberry muffin syndrome can be caused by several infectious agents (toxoplasmosis, rubella, CMV, HSV, etc.) and blood disorders, in particular acute myeloid leukaemia.
Enteroviruses can be responsible for exanthema during the neonatal period. Recently, parechoviruses (3) were associated with a characteristic clinical presentation with:
- signs of meningoencephalitis
- maculopapular exanthema affecting the hands and feet
- abdominal distension
- a clinical presentation of sepsis without elevated CRP levels
Due to the upsurge in syphilis in Europe, in women in particular, we are once again observing presentations of congenital syphilis in which delays in diagnosis and treatment are lift-threatening to the child.
NTED, or neonatal toxic shock syndrome-like exanthematous disease, is defined by a widespread cutaneous rash, fever of > 38°C, thrombocytopenia, low CRP, and no other identified cause. It is equivalent to toxic shock syndrome related to aStaphylococcus aureus strain secreting a superantigenic toxin (most often TSST-1). Unlike toxic shock syndrome in adults, NTED has a fairly good prognosis.
In addition to infectious causes, autoimmune, genetic and metabolic diseases can also be responsible for neonatal rashes; lupus warrants a few reminders:
- occurs between day 1 and day 60;
- 62% of mothers are asymptomatic;
- a maternal anti-SSA level > 50 units/ml is a risk factor for neonatal lupus;
- 10% of children will have first- to third-degree atrioventricular block.
In the presence of a rash in a newborn, the following signs should sound a warning:
- Irritability, disturbances of consciousness;
- Loss of appetite, lack of weight gain;
- Pale and grey skin, increased skin-recolouring time;
- Thrombocytopenia, leukocytopenia and high CRP levels.
Professor Mario Cutrone reviewed iatrogenic dermatological conditions in the neonatal period. Of these, there are two particularly interesting situations:
- the risk of haemolysis when applying henna in G6PD-deficient children;
- the publication of cases of cytosteatonecrosis following hypothermia for brain protection in neonatal intensive care.
Regarding children with atopic dermatitis, Professor Carsten Flohr pointed out that only 10% of children with atopic dermatitis will develop the traditional pattern of the atopic march.
Of the environmental factors involved in the occurrence of AD, water hardness appears to have an impact only in children with filaggrin mutations. In an English study of 4141 children aged 4 to 16 years, exposure to hard water during cleansing significantly increased the risk of developing AD from the 3rd month with an OR of 1.47 (1.12-1.92).
Skin barrier impairment increases the penetration of allergens. The skin plays an essential role in the sensitisation of atopic children, including for food allergies such as peanut allergies.
Ten years after the first publication identifying mutations in the filaggrin gene, Professor Alan Irvine reported current data on the skin barrier in AD; patients with mutations are significantly at risk for developing a peanut allergy.
Regional skin characteristics can explain the topography of atopic dermatitis based on age. A study of 1000 children aged 4 to 72 months including a genetic analysis of FLG and a biochemical skin analysis of various anatomical zones showed slower maturation of the skin barrier at cheek level (immature corneocytes, lack of NMF).
All of these data suggest that early intervention aiming to restore the skin barrier, in particular on the cheeks, would have preventive action; this needs to be confirmed by additional clinical studies.