[Metameric macular and papular skin mastocytosis]. / Mastocytose cutanée maculopapuleuse métamérique.

BACKGROUND: Mastocytosis is characterised by the presence of abnormal quantities of mastocytes in one or more organs. Although it occurs in systemic forms of mastocytosis, isolated skin involvement is the predominant presentation, particularly in children, in the form of more or less extensive though non-systematic lesions. Herein, we report a case of maculopapular cutaneous mastocytosis that is unusual in terms of its metameric topography. PATIENTS AND METHODS: A 16-year-old youth presented with an erythematous maculopapular rash of 18 months' duration and involving pruritic inflammatory episodes strictly localised in segment T8 to the left. The skin biopsy showed a significant increase in the number of dermal mastocytes (CD117+). No KIT mutations were found in the skin lesions nor in the unimpaired skin of the opposite side. Further investigations ruled out systemic mastocytis. DISCUSSION: Herein, we report a case of cutaneous mastocytosis that is unusual in terms of its metameric disposition. There have been only two previous reports of segmental cutaneous mastocytis. The two pathological hypotheses involved precessional dermatitis that renders the skin surface susceptible to homing, and somatic mosaicism (type 1) with local mastocyte proliferation.

[What's new in clinical dermatology?] / Quoi de neuf en dermatologie clinique ?

Zika virus: what the dermatologist should know. Probably a new vaccine against herpes zoster and postherpetic neuralgia in older adults. Defining moderate, significant and extensive types of pemphigus with ABSIS et PDAI scores. Biologic Therapies and serious infections in patients with psoriasis. We can be cautiously optimistic, in that tuberculosis is rare but still occurs despite adherence to tuberculosis prevention guidelines. Others serious infections are rare, mainly pneumonia and cellulitis. Hidradenitis suppurativa: an unrecognized paradoxical effect of biologic agents. There is an association between Inflammatory Bowel Disease (IBD) and Hidradenitis suppurativa (HS), mostly with Crohn's disease, suggesting the need to look for signs and symptoms of IBD in HS patients. A study of 550 twins found that genetic and environmental factors each contribute to approximately half of the score of rosacea. Telangiectasia Macularis Eruptiva Perstans is a difficult to diagnose type of mastocytosis, often with a delay and which is associated with a systemic involvement in 50% of cases. Vitiligo. Management and development of new scores for the dermatologist and the patient. Livedoid vasculopathy. Anticoagulation with new molecules could prove an efficient means of treatment. Pyoderma Gangrenosum. Don't forget the toxic etiology. Daily practice: Laboratory monitoring for liver function tests and serum lipid profile during isotretinoin therapy for acne is currently recommended at baseline and every 3 months, depending on the results. Daily practice: Mikailov and al., challenge our habits by their medico economic study and propose an empirical treatment with terbinafine for patients with suspected onychomycosis that is cost effective with minimal effect on patient safety as terbinafine-induced liver injury is very rare. It makes think and especially propose studies to update our recommendations.

[Vulvar oedema revealing systemic mastocytosis]. / Œdème vulvaire révélant une mastocytose systémique.

BACKGROUND: Systemic mastocytosis is characterised by abnormal proliferation of mast cells in various organs. We report an original case of systemic mastocytosis revealed by vulvar oedema. PATIENTS AND METHODS: A 24-year-old patient was examined in the dermatology department for vulvar oedema appearing during sexual intercourse. She presented vasomotor dysfunction of the lower limbs, urticaria on the trunk on exertion, diarrhoea and bone pains. Laboratory tests showed serum tryptase of 29.7µg and plasma histamine at twice the normal value. Myelogram results showed infiltration by dysmorphic mast cells. Screening for c-kit D816V mutation was positive. Duodenal biopsies revealed mast-cell clusters with aggregation involving over 15 mast cells. CD2 staining was inconclusive and CD25 staining could not be done. Trabecular osteopenia was found, and we thus made a diagnosis of indolent systemic mastocytosis (ISM variant Ia) as per the WHO 2008 criteria. Symptomatic treatment was initiated (antiH1, H2, antileukotrienes) and clinical and laboratory follow-up was instituted. DISCUSSION: The cutaneous signs leading to diagnosis in this patient of systemic mastocytosis involving several organs were seemingly minimal signs associated with mastocyte degranulation. This is the third recorded case of mastocytosis revealed by vulvar oedema and the first case revealing systemic involvement. The two previously reported cases of vulvar oedema revealed cutaneous mastocytosis alone. Mastocytosis, whether systemic or cutaneous, must be included among the differential diagnoses considered in the presence of vulvar oedema.

[IgE mediated anaphylaxis in a patient with systemic mastocytosis]. / Anaphylaxie médiée par les IgE chez un patient atteint de mastocytose systémique.

BACKGROUND: Anaphylaxis is a severe, generalized, life-threatening reaction of rapid onset. We report the case of a patient presenting several systemic anaphylactic reactions over many years, initially ascribed to a cereals allergy but which finally proved to be due to systemic mastocytosis hidden for a long time. PATIENTS AND METHODS: A 53-year-old man consulted for an eruption consisting of monomorphic pigmented maculopapular lesions on the trunk associated with itching and urticaria. He was a farmer and presented severe sensitivity to cereals, with anaphylaxis, which continued despite withdrawal of these allergens. Skin and bone marrow infiltration, abnormal mast cells, positivity for c-kit 816 mutation and the persistent elevation of serum tryptase enabled a diagnosis of indolent systemic mastocytosis to be made. DISCUSSION: In systemic mastocytosis anaphylaxis is an expected complication relating to the proliferation of mast cells and a massive increase in mediator release (non-immunological mechanism). All patients with severe and recurrent anaphylaxis should be analyzed for underlying mastocytosis by careful physical examination and assay of baseline tryptase.

[Influenza A: H1N1 post-viral membranoproliferative glomerulonephritis occurring in aggressive systemic mastocytosis: Case report and literature review]. / Glomérulonéphrite membrano-proliférative post-grippale chez un patient atteint de mastocytose systémique agressive : observation commentée et revue de la littérature.

Systemic mastocytosis is characterised by tissular infiltration and a cytokine storm due to mast cells excessive proliferation and activation. Herein, we report an extraordinary case of AH1N1 influenza post-viral glomerulonephritis occurring in the course of an aggressive systemic mastocytosis with an associated hematological neoplasm. Because of a multisystemic involvement including the liver and lungs, we treated mastocytosis with midostaurin (multiple inhibitor of kinase protein), anti H1/H2 blockers and dexamethasone as first line treatment. One month later and despite vaccination, he developed a severe acute lung injury with respiratory distress due to AH1N1 influenza in association with the nephrotic syndrome. Kidney biopsy disclosed a membranoproliferative glomerulonephritis that was successfully treated with mycophenolate mofetil. Only a few cases of influenza post-viral or post-vaccination glomerulonephritis are documented in the medical literature. This is an exceptional association of uncommon conditions occurring within only a few months in the same patient.

Fatal hymenoptera venom anaphylaxis by undetected clonal mast cell disorder: A better identification of high risk patients is needed.

Hymenoptera venom anaphylaxis is the most frequent cause of anaphylaxis and responsible for about 20% of all fatal anaphylaxis cases in adults. We report two cases of fatal hymenoptera venom anaphylaxis with undiagnosed underlying mastocytosis and review the risk factors for severe or fatal hymenoptera venom anaphylaxis, as well as the specificities of its association with mastocytosis. As hymenoptera venom allergic patients with underlying clonal mast cell disorder generally lack typical skin lesions of mastocytosis, its diagnosis can easily be missed, underscoring the importance and need for diagnostic strategies in order to correctly identify these patients. Predominant cardiovascular symptoms in the absence of urticaria or angioedema following an insect sting are suggestive of underlying clonal mast cell disorder, and should be distinguished from panic attack or vasovagal syncope. Similarly, an unexplained syncope or an "idiopathic" anaphylaxis might reveal mastocytosis or hereditary alpha-tryptasemia. Acute and basal serum tryptase measurements should always be integrated in the diagnostic work-up of an insect sting reaction or unexplained syncope or shock of any origin.

[Tryptase: A practical guide for the physician]. / Dosage de la tryptase : un guide d'utilisation pour le clinicien.

Tryptase is the most abundant endopeptidase released by mast cells degranulation, involved in many pro and anti-inflammatory processes. Normal serum tryptase range is 0-11.4 µg/L. Tryptase is a useful diagnostic tool for anaphylaxis, systemic mastocytosis (SM) and mast cell activation syndrome (MCAS), where specific threshold values must be used. SM diagnosis criteria include evidence of dense mast cell infiltrate either in the bone marrow or the affected organ (such as skin), presence of KIT D816V mutation and elevated serum tryptase level (>20 µg/L). In SM, tryptase level is correlated with the burden of mast cells in bone marrow. MCAS should be considered in case of severe and recurrent typical clinical signs of systemic mast cell activation involving at least two organs, associated with an increase in serum tryptase level of 20% + 2 µg/L from the individual's baseline. Anaphylaxis is the most severe among hypersensitivity reactions. A clonal mast cell disorder is a central question in anaphylaxis and appropriate explorations should be conducted in these patients. Triggers for anaphylactic reactions vary significantly in the general population and in patients with MS or MCAS. Finally, physicians must be aware of the many pathological and physiological situations that affect tryptase levels.

[Uncommon dermatologic disorders triggered by radiation therapy of breast cancer: A case-series]. / Dermatoses réactionnelles rares après radiothérapie : une série de cas avec cancer du sein.

Radiotherapy's main skin toxicities are now well-separated, acute (acute radiation dermatitis) or chronic complications (chronic radiation dermatitis, induced cutaneous carcinoma, aesthetic sequelae). Exceptionally, radiotherapy may induce, by isomorphic reaction or Koebner's phenomenon, some specific dermatosis. In this article, we report five new observations of these unusual complications of radiation therapy, occurring in very variable time after breast irradiation and remaining strictly localized in the irradiated field (cutaneous mastocytosis, Sweet syndrome, lichen planus, vitiligo). These cases emphasize the need to realize a systematic histological exam if any atypical skin lesion appears after radiotherapy, even long after.

[Causes and differential diagnosis of flush]. / Étiologies et orientation diagnostique devant un flush.

The flush is a transient and recurrent erythema of the upper region of the body, due to a sudden arterial dilatation. First, physicians should confirm the flush and ascertain the location and timing of skin manifestations. The rapid onset and location of the skin rash to the face and anterior chest are the main characteristics of flush. In most of the cases, the flush is emotional, but this should remain a diagnosis of exclusion, as flush may be the presenting manifestation of many systemic or neoplastic disorders. Therefore, a comprehensive diagnostic work-up is necessary, including clinical, biological, and imaging testing. Neoplastic and endocrine causes of flush include VIPoma, carcinoid syndrome, medullary thyroid cancer, mastocytosis, renal cell carcinoma, and pheochromocytoma. Mast cell activation syndrome has been recently described, but it remains a diagnosis of exclusion. This review will first present the different causes of flush, and then will propose a diagnostic algorithm for the physician.