The most frequent clinical form of mastocytosis was urticaria pigmentosa followed by mastocytoma and diffuse cutaneous mastocytosis. Darier's sign was present in 94% of cases. A negative Darier's sign does not rule out mastocytosis. In contrast to adults, mastocytosis in children usually has a benign course making sophisticated or invasive diagnostic tests unnecessary. A classification of paediatric cutaneous mastocytosis is proposed.

SummaryBuruli disease (BU) is a progressive necrotic and ulcerative disease of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU is considered the third most common mycobacterial disease after tuberculosis and leprosy. Three clinical stages of the cutaneous lesions have been described in BU: preulcerative, ulcerative and healed lesions. In this study we used immunohistochemistry and automated morphometry to determine the percentage of macrophages and of CD4/CD8 lymphocytes and their expression of interferon (IFN)-γ γ γ γ , interleukin (IL)-10, tumour necrosis factor (TNF)-α α α α and transforming growth factor (TGF)-β β β β . Expression of these cytokines was correlated with the inflammatory response evaluated by histopathology. All the studied BU ulcerative cases showed extensive necrosis and chronic inflammation. The most important feature was the presence or absence of granulomas co-existing with a mixed pro-inflammatory/anti-inflammatory cytokine balance. When granulomas were present significantly higher expression of IFN-γ γ γ γ was seen, whereas in ulcerative lesions without granulomas there was increased expression of IL-10 and significantly higher bacillary counts. These features correlated with the chronicity of the lesions; longer-lasting lesions showed granulomas. Thus, granulomas were absent from relatively early ulcerative lesions, which contained more bacilli and little IFN-γ γ γ γ , suggesting that at this stage of the disease strong suppression of the protective cellular immune response facilitates proliferation of bacilli.

Incontinentia pigmenti is a rare genodermatosis in which the skin involvement occurs in all patients. Additionally, other ectodermal tissues may be affected, such as the central nervous system, eyes, hair, nails and teeth. The disease has a X-linked dominant inheritance pattern and is usually lethal to male fetuses. The dermatological findings occur in four successive phases, following the lines of Blaschko: First phase - vesicles on an erythematous base; second phase - verrucous hyperkeratotic lesions; third phase - hyperchromic spots and fourth phase - hypochromic atrophic lesions.

Inherited epidermolysis bullosa is a group of genetic diseases characterized by skin fragility and blistering on the skin and mucous membranes in response to minimal trauma. Epidermolysis bullosa is clinically and genetically very heterogeneous, being classified into four main types according to the layer of skin in which blistering occurs: epidermolysis bullosa simplex (intraepidermal), junctional epidermolysis bullosa (within the lamina lucida of the basement membrane), dystrophic epidermolysis bullosa (below the basement membrane), and Kindler epidermolysis bullosa (mixed skin cleavage pattern). Furthermore, epidermolysis bullosa is stratified into several subtypes, which consider the clinical characteristics, the distribution of the blisters, and the severity of cutaneous and extracutaneous signs. Pathogenic variants in at least 16 genes that encode proteins essential for the integrity and adhesion of skin layers have already been associated with different subtypes of epidermolysis bullosa. The marked heterogeneity of the disease, which includes phenotypes with a broad spectrum of severity and many causal genes, hinders its classification and diagnosis. For this reason, dermatologists and geneticists regularly review and update the classification criteria. This review aimed to update the state of the art on inherited epidermolysis bullosa, with a special focus on the associated clinical and genetic aspects, presenting data from the most recent reclassification consensus, published in 2020.

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