[Bullous dermatitis with multinucleated keratinocytes in dermatitis artefacta: A case report]. / Dermatose bulleuse avec kératinocytes multinucléés révélant une dermatose factice : à propos d'un cas et revue de la littérature.

We report the case of a 13-year-old young lady with a one year reccuring bullous dermatitis history for which the diagnostic hypothesis of dermatitis arterfacta was made. This hypothesis was made by the pathologist, without it being suggested by the dermatologist, after observing singular histological lesions coresponding to a cutaneous blister associated with epidermic necrosis with multinucleated keratinocytes. When dermatitis artefacta is suspected, a biopsy is usually conducted to rule out differential diagnosis such as auto-immmune dermatitis when there is a blister. Confession from patients is rarely obtained. Therefore, having positive histogical clues for dermatitis artefacta would be of a great use to help making the diagnosis in difficult cases.

[Hemorrhagic bullous dermatosis (HBD): A rare side-effect of heparins]. / Dermatose bulleuse hémorragique (DBH) : un effet indésirable rare des héparines.

BACKGROUND: Bullous haemorrhagic dermatosis (BHD) induced by heparin is a rare and benign side effect of which we report two cases. PATIENTS AND METHODS: Case 1: an 81-year-old man presented haemorrhagic bullae on the limbs and trunk 7 days after starting enoxaparin. The laboratory haemostasis assessment was normal. A diagnosis was made of BHD induced by enoxaparin and the patient's treatment was switched to apixaban, resulting in a favourable outcome with resolution of the lesions within 15 days. Case 2: a 71-year-old woman hospitalised for pulmonary embolism was given tinzaparin. At two months of treatment, haemorrhagic bullae were observed on her forearms at distance from the injection sites. A diagnosis of BHD induced by tinzaparin was made. Treatment with tinzaparin was continued and the lesions resolved within 15 days. DISCUSSION: Heparin-induced BHD is a rare entity initially described in 2006. Ninety-five cases of heparin-induced BHD have been reported. It is characterized by multiple haemorrhagic bullae at a distance from the injection sites. Time to onset of lesions after heparin initiation ranges from 24h to 4 months. Laboratory assessment should be routinely performed to rule out any haemostasis disorders. Lesions subside within 15 days whether heparin is continued or withdrawn. CONCLUSION: Heparin-induced BHD is a rare but benign side effect of heparins. In the absence of recommendations, therapeutic management should be adapted to the individual situation.

[Oesophageal bullous detachment with massive haemorrhage revealing acquired haemophilia A in autoimmune bullous dermatosis]. / Décollement bulleux de l'œsophage responsable d'une hémorragie massive révélant une hémophilie A acquise au cours d'une dermatose bulleuse auto-immune.

INTRODUCTION: Acquired haemophilia A (AHA) is a rare coagulopathy caused by the development of factor VIII antibodies. Various aetiologies have been established but a number of cases have been reported in association with autoimmune bullous dermatosis (AIBD). We report a new case of this type of association revealed by oesophageal involvement of AIBD. PATIENTS AND METHODS: A male patient was treated for AIBD. Due to the inefficacy of local steroids and the emergence of oral and laryngeal blisters, the patient was treated with systemic steroids. He developed a gastrointestinal haemorrhage complicated by haemorrhagic shock. Endoscopy revealed complete peeling of the oesophagus. Laboratory tests showed lengthening of ACT, reduced factor VIII levels, and the presence of anti-factor VIII antibodies. A diagnosis was made of AHA associated with AIBD. Prolongation of systemic corticosteroids and initiation of rituximab resulted in normalisation of haemostasis. DISCUSSION: AIBD and AHA frequently develop concomitantly, as was the case with our patient. The haemorrhagic complications were severe. The aim of AHA treatment is to stop acute bleeding and eliminate antibodies, and for this reason rituximab was chosen. CONCLUSION: Oesophageal bullous detachment is rare in AIBD but, as seen here, it may be responsible for massive haemorrhage, especially in the event of associated AHA. This feature underscores the need for evaluation of haemostasis in the early stages and during relapses for all patients with AIBD.

[Humoral immune diseases: Cutaneous vasculitis and auto-immune bullous dermatoses]. / Immunité à médiation humorale : vascularites cutanées et maladies bulleuses auto-immunes.

Humoral immunity is the cause of multiple diseases related to antibodies (IgA, IgG, IgM) produced by the patient. Two groups of diseases are identified. The first group is related to circulating antigen-antibody complexes. The antigens are various. They are often unknown. These immune complexes cause a vascular inflammation due to the complement fixation. Consequently, this group is dominated by inflammatory vasculitis. In the second group, the pathology is due to the fixation in situ of antibodies to a target antigen of the skin that is no more recognized by the patient. This group is represented by the auto-immune bullous dermatoses.

Bullous pemphigoid, a dermatosis of the elderly / La pemphigoïde bulleuse, une dermatose du sujet âgé

Bullous pemphigoid, a dermatosis of the elderly. Bullous pemphigoid is the most common autoimmune bullous disease and affects almost exclusively the elderly. Its occurrence is related to the presence of pathogenic autoantibodies directed against structural proteins (BP180 and BP230) of the protein adhesion complex of the dermo-epidermal junction: the hemi-desmosome. Bullous pemphigoid is classically characterized by pruritus and the appearance of blisters on an inflammatory background with a symmetrical topography: thighs, arms and trunk. Blisters eventually break, leading to erosions. Mucosal involvement is rare. Histology of a cutaneous biopsy finds a subepidermal blister containing eosinophils. Direct immunofluorescence confirms the diagnosis by the presence of linear deposits of IgG and C3 along the epidermal basement membrane. The reference treatment is the superpotent topical corticosteroid therapy (clobetasol propionate).

La pemphigoïde bulleuse, une dermatose du sujet âgé. La pemphigoïde bulleuse est la dermatose bulleuse auto-immune la plus fréquente et elle touche quasi exclusivement la personne âgée. Sa survenue est liée à la présence d'autoanticorps pathogènes dirigés contre des protéines de structure (BP180 et BP230) du complexe protéique d'adhésion de la jonction dermo-épidermique : l'hémidesmosome. La pemphigoïde bulleuse se manifeste classiquement par un prurit et l'apparition de bulles sur fond inflammatoire avec une topographie symétrique : cuisses, bras, tronc. Les bulles finissent par se rompre, laissant la place à des érosions. L'atteinte muqueuse est rare. L'histologie d'une biopsie cutanée montre une bulle sous-épidermique contenant des polynucléaires éosinophiles. L'immuno- fluorescence directe affirme le diagnostic par la présence de dépôts linéaires d'immunoglobuline de type G et de C3 le long de la membrane basale épidermique. Le traitement de référence est la corticothérapie locale très forte (propionate de clobétasol).

[Epidermolysa bullosa acquisita and graft-versus-host disease]. / Épidermolyse bulleuse acquise et réaction du greffon contre l'hôte.

BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a rare acquired blistering disorder caused by production of auto-antibody directed against type-VII collagen. Autoimmune disorders can occur after allogenic bone marrow transplantation as manifestations associated with chronic graft-versus-host disease (GVHD). To date, there have been 10 cases reported in the literature concerning autoimmune blistering diseases following allogenic stem-cell transplants. Herein we describe a new case involving EBA. OBSERVATION: A 46-year-old woman developed EBA 4 years after allogenic cord blood transplantation for non-Hodgkin T-cell lymphoma complicated by acute digestive and cutaneous GVHD. At physical examination, she had some cutaneous blisters on the abdomen, arms and face, as well as numerous erosions in the buccal cavity. Direct immunofluorescence microscopy revealed linear IgG and C3 deposits along the dermal-epidermal basement membrane zone. Indirect immunofluorescence showed weak IgG G4 anti-basement membrane zone antibodies, which reacted with the dermal side of 1M NaCl-split skin; the autoantibodies were directed against type-VII collagen. This second case of EBA was evocative of a GVHD blistering disease. After the therapeutic failure of dapsone and of combined mycophenolate-prednisone, treatment with rituximab proved effective. DISCUSSION: EBA may form part of the autoimmune signs associated with chronic GVH. The destruction of basement membrane and of epidermal basal cells that occurs in GVH could give rise to autoimmune bullous disease. However, in our patient, in whom manifestation of chronic GVH was restricted to the lungs, it is difficult to rule out the fortuitous onset of EBA, which presented at a sizeable interval after acute GVH.