The subjects with NF1 present some characteristic bone abnormalities. Among the latter there is tibial dysplasia, which is usually located between the middle third and the distal third of the tibia (2). In this site there is thinning of the bone, due to narrowing of the medullary, whereas the cortical can be normal or thickened. The weakening of the bone is responsible for an anterolateral bending of the tibia -tibia procurvata et vara- (2). The latter can be complicated by pathological fractures and mainly by defective formation of bone callus and non rejoining of the two fragments (pseudoarthrosis). The bone fragility is partly due to an increased osteocyte-related micro-porosity with persistence of ectopic blood vessels, hypomineralization, and generalized defect of organic matrix formation (1).
Telangiectasia is clinically a reddish-blue linear lesion that disappears under fingers pressure; more telangiectases can be grouped with each other while maintaining their individuality. On the other hand, port-wine stain is a reddish-blue, flat stain of uniform color in which isolated vessels can not be seen to the naked eye. Both nevoid telangiectases and port-wine stain can be congenital or acquired. In this work starting from two clinical cases of unilateral nevoid telangiectasia and acquired port-wine stain, both acquired in the prepubescent age, we analyze the differences and similarities between the two diseases.
Molluscum contagiosum and superficial lymphangioma are two very different disorders. However, their lesions, size and tendency to cluster are similar, so that in some cases, when lymphangioma has appeared recently, some diagnostic doubt may arise.
The cutaneous disorders involving the nose and its covering skin are affected by the peculiar characteristics of this region. First of all by the particular position of the nose, with its visibility and protrusion; moreover, by the characteristics of its skin, clinging to the underlying layers, scarcely liftable in folds and rich in sebaceous glands and finally by the continuity between the mucosa and the skin covering the nose level with the external nose orifices (...).
The seborrheic variant of pemphigus foliaceus affects the seborrheic regions, mainly the scalp (1, 3), in absence of mucosal lesions. The erythematous variant is characterized by lesions on photoexposed areas and by IgG and C3 deposits both interkeratinocytic and at the dermal-epidermal junction. Overlap forms do exist as shown by our case. Histologically, there is superficial acantholysis with isolated keratinocytes level with the granular layer (2). The immunofluorescence shows a high pemphigus phenomenon and, sometimes, lupus erythematosus-like findings (4). The clinical differential diagnosis from impetigo and eczema is particularly difficult in children The prognosis is usually benign and the disorder can be sometimes controlled by topical corticosteroids.
The herpetiform variant of pemphigus foliaceus is characterized, besides the lack of mucosal lesions, by intense itching, circinate, papulo-pomphoid lesions, vesicles and crusts, good response to oral corticosteroids and benign clinical course. In children pemphigus foliaceus is rare and the herpetiform variant exceptional (1, 5). The histological examination (1, 3) shows superficial eosinophilic spongiosis. The immunofluorescence shows deposits of IgG e C3 in the intercellular space of epidermis. The diferential diagnosis should rule out dermatitis herpetiformis and IgA linear dermatitis (2, 4). The direct and indirect immunofluorescence, showing the typical intercellular deposits, is essential to rule out other disorders and confirm the diagnosis of pemphigus herpetiformis.
We know many disorders distributed according to the Blaschko lines, thanks to the relevant reports of Rudy Happle and many other Authors. How-ever, many problems are still open to discussion and some of them have significant clinical implications. An interesting problem regards the clinically silent nevus (3), namely a nevus condition that is clinically invisible until when it is unveiled by an exogenous agent. This concept is necessary to understand the numerous acquired diseases distributed according to the Blaschko lines. Some of these disorders such as lichen striatus and blaschkitis exist only in a segmentary form, whereas others such as fixed drug eruption, lichen ruber planus, lichen sclerosus, lichen nitidus, lupus erythematosus, psoriasis, pemphigus, lichenoid eruptions and vitiligo usually affect the entire skin surface, but sometimes may exist in a segmentary form and thus be distributed according to the Blaschko lines. In the latter case there are two possibilities as follows: the skin disease affects only a cutaneous segment or, alternatively, the skin disease bilaterally affects a more or less large skin surface, but it is more marked in one segment. All these acquired skin disorders can be explained by the existence from the fetal life in one cutaneous segment of a clone of mutated cells. The mutation consists in a predisposition of the cell to display pathological manifestations when coming into contact with a triggering factor (...).
Both streptococcus and staphylococcus, thanks to their pyrogenic and vasodilating toxins, can be responsible for fever and generalized reddening of the skin. Clinical features like those, when associated to an enanthem and cultures growing group A β-hemolytic Streptococcus, lead to diagnose streptococcal scarlet fever. On the other hand, when there is no enanthem and bacteriological cultures from the pharynx do not grow group A β-hemolytic Streptococcus, drug or virus exanthem is often suspected and antihistaminics or corticosteroids are given, without taking into account that clinical features superimposable to streptococcal scarlet fever can be due to Staphylococcus aureus and its toxins. Staphylococcal scarlatina is an initial or mild variant that can result in more severe toxic syndromes, such as staphylococcal scalded skin syndrome and toxic shock syndrome.
The ear and its covering skin have some peculiar characteristics and, moreover, some characteristics similar to those ones of the nose such as exposure, cartilaginous structure, less extensible skin and abundant sebaceous glands. Some of these anatomic and physiological characteristics can influence several dermatological disorders. We should remember the abundant vessels and the susceptibility to vasomotor crises, the numerous sebaceous glands in the concha and the modified sweat glands in the bony portion of the external auditory duct, which are responsible for the secretion of cerumen and the presence of grooves and reliefs, which make the surface of the auricle very irregular. Finally, we should remember the retroauricular fold, which is often affected in many inflammatory constitutional skin diseases such as atopic dermatitis, psoriasis and seborrheic dermatitis (...).
Clinical features. Fetal hemangioma completely matures “in utero”. This is why it can be shown by ultrasonography in the second trimester of pregnancy. Fetal hemangioma mainly affects the face and lower limbs. At birth it appears as a purplish, up to 15 cm in size tumor with ectatic vessels, sometimes with a central crust or ulceration. Pathological findings. Lobules of endothelial cells with some mitoses and large, thin-walled vessels stay within a densely fibrotic stroma. The latter contains deposits of hemosiderin and focal thrombosis and sclerosis. Unlike common hemangioma, its cells do not react with GLUT-1 and LeY antigens. Prognosis. Characteristically, fetal hemangioma is already fully developed at birth. It does not grow anymore and rapidly regresses within 6-18 months with atrophic scars.