From vascular anomalies to genodermatoses

Doctors Peter Hoeger from Hamburg, Christine Labrèze from Bordeaux and Eulalia Baselga from Barcelona led the debates with a seminar on vascular anomalies, offering a wonderful example of the European dimension of this congress and lively discussions! Among today's other topics; a review of therapeutic progress in epidermolysis bullosa and the current situation of scabies in children. We hope you find it helpful!

Scabies

Professor Franck Boralevi gave a presentation on scabies. The main characteristics of scabies were addressed, with a specific focus on children:

  • Scabies affects 300 million people around the world every year. In France, there are approximately 350 cases per 100,000 inhabitants per year.
  • The higher the number of parasites, the higher the risk of transmission. In traditional cases of adult scabies, there are 12 female mites on average.
  • It generally takes two months to diagnose.
  • The characteristics of scabies in children are as follows:

            - There is itching in family members in 50 % of cases. Severe itching is less common in children;
            - Nodules with scabies are more common in children (2/3 of children), in particular in the axilla. However, nodules on the scrotum are less common than in adults (5 % vs. 16 %);

            - The hands and feet, and face and scalp are more commonly affected (respectively 60 %, 20 % and 27 %). Mammary regions are affected less often compared to infections in adults (9 % vs. 17 %).
            - The main differential diagnoses are atopic dermatitis, Langerhans cell histiocytosis and infantile acropustulosis.

  • The treatment of scabies in children:

           - The treatment of scabies relies on local treatments (permethrin, benzyl benzoate) or ivermectin;
           - It is important to underline the need to hold a follow-up consultation on day 28 to ensure recovery.

Epidermolysis bullosa

In his conference on genodermatoses, Professor John McGrath described encouraging therapeutic breakthroughs in epidermolysis bullosa dystrophica:

  • The observation of areas still free of blisters demonstrates the existence of mosaicism where cellular clones have the ability to synthesise type VII collagen. Autografting from these normal areas has helped heal resistant regions.
  • Mesenchymal stem cells can improve wounds by means of immuno-modulating and anti-inflammatory factors. Intravenous injection of allogeneic mesenchymal stem cells resulted in clear clinical improvement without locally increasing the level of type VII collagen in ten treated patients.
  • Bone marrow transplantation seems effective, but with the toxicity of immunosuppressive agents and questions regarding the exact mechanism and fate of these pluripotent stem cells.
  • A phase-1 gene therapy study is currently in progress. A viral vector (SIN lentiviral vector) is used to introduce the normal copy of the type VII collagen gene.

Vascular anomalies

During the symposium on vascular anomalies, Peter Hoeger reviewed various vascular tumours in children.

Haemangioma remains the most common, accounting for 99% of cases. In other cases, it is important to clarify the diagnosis in order to avoid complications. Tufted angioma and haemangioendothelioma are at risk for Kasabach-Merritt syndrome. . Blue rubber bleb syndrome is at risk for sometimes massive intravisceral bleeding. PILA (papillary intralymphatic angioendothelioma) is a borderline lesion with a low risk of metastasis.

Glomangiomas, RICH, NICH and PICH, and verrucous haemangioma are benign and pose only a potential aesthetic problem.

Dr Christine Léauté-Labrèze:

Propranolol is the first-line treatment for infantile haemangiomas. Dr Christine Léauté-Labrèze reviewed the results of a study assessing propranolol. After six months of treatment, complete resolution was observed in 60 % of the children in the propranolol group versus 4 % in the placebo group. On cessation of treatment, recolouring was observed for 20 % of the children and partial recurrence of the haemangioma was observed for 10 to 15 %.

Timolol has no marketing authorisation (MA) for the treatment of haemangiomas. Nonetheless, this treatment may be of interest in the treatment of superficial haemangiomas. This treatment should be evaluated after four weeks; if there is no improvement, cessation of treatment or indication of treatment with oral propranolol should be considered. Treatment should be continued for six months to achieve significant improvement. In this indication, there seems to be systemic absorption of timolol, in particular in premature infants.

Medications inhibiting the mTOR pathway including rapamycin are promising molecules in the treatment of vascular and lymphatic malformations. Rapamycin could become the first-line treatment for Kasabach-Merritt syndrome. Broader studies will be necessary to confirm this first-line treatment. This molecule is also under evaluation for other vascular and lymphatic malformations. Thanks to genetics, we better understand the molecular mechanisms involved in these malformations. These breakthroughs are paving the way for targeted therapies.