Edouard Grosshans

Ectopic contact dermatitis from ethyl cyanoacrylate instant adhesives

Although allergic reactions to cyanoacrylate adhesives are extremely rare, they should not be considered impossible. We report a young hairdresser who developed an occupational allergic‐contact dermatitis to 2 “instant glues” used to attach false hair. The eczematous eruption involved the fingers and face slightly but mainly the eyelids. Patch test reactions were strongly positive to ethyl cyanoacrylate adhesives.

Patch test reactions to mite antigens: a GERDA* multicentre study

We performed patch tests with Dermatophagoides pteronyssinus (Dp) antigen from 2 different sources in 355 non‐randomly selected patients with atopic dermatitis(AD) and 398 subjects of a control group. The study demonstrated that contact sensitization to mites occurred in an appreciable% of AD cases(20.8%). Using commonly available assay products. The differences recorded between the 2 materials tested were related to the concentration of P1 antigen. Non‐atopic patients rarely showed positive reactions to Dp (0.75%), when strict criteria for readings were applied and if 2 readings were performed, Patients with positive patch tests did not necessarily show positive immediate skin tests. It would be useful to carry out tests systematically in atopic patients, even if it is not yet known what modern treatment would be best for the patient. Laboratories still do not provide standardized house dust mite preparations measuring and codifying their biological acitivity for use in patch of better test materials, in syringes with homogeneous dispersion and concentration.

ATPase and morphologic changes in Langerhans cells induced by epicutaneous application of a sensitizing dose of DNFB

We have previously described an ATPase Langerhans cell (LC) staining technique allowing progression from light to electron microscope observation. Using this technique we have studied, following epicutaneous application of a sensitizing dose of a hapten, 2,4-dinitro-1-fluorobenzene (DNFB), the fate of the epidermal LC located in the sensitization zone. We wanted to know, under the light microscope, if the density and/or morphology of the LC are modified by such a treatment and, under the electron microscope, what are the ultrastructural changes accompanying the possible light microscope modifications. Under the light microscope, the observation of LC during the 5 d necessary for the development of contact sensitivity to DNFB shows that their number drops in the course of the first 24 h to normalize again 3 d later. Under the electron microscope, observations over the first 24 h revealed that LC remained in the epidermis, but were ATPase-negative. The disappearance of the membrane ATPase activity took place while the LC presented an increased number of coated pits, coated vesicles, endosomes, and lysosome organelles which characterize, at the ultrastructural level, the process of receptor-mediated endocytosis (RME). Following RME, many Birbeck granules (BG) appeared in the cytoplasm. Thus, epicutaneous application of DNFB leads to an endocytic activation of LC. However, the ligand(s) and/or the cell-surface components, which probably internalize during the RME process, remain unknown.

Trichilemmal cyst with intrinsic parietal sebaceous and apocrine structures.

The trichilemmal cyst has been the subject of numerous light and ultrastructural studies. To our knowledge, no glandular differentiation has so far been described within the wall of such a cyst. We report a case in which there was evidence of sebaceous and apocrine differentiation within the cyst wall. It is postulated that these features suggest that it should be classified amongst the pilar adenomas.