Cyclic catamenial dermatoses.

Circulating sex hormones follow major fluctuations during the ovarian cycle. The so-called premenstrual syndrome represents a global condition grouping the diversity of catamenial disorders. At the skin level, the sebaceous gland activity is obviously modulated by these endocrine fluctuations. In addition, a series of pathological manifestations take place simultaneously in some women. Among them, the most frequent skin condition is represented by catamenial acne. Concurrently, the autoimmune progesterone dermatitis refers to a diversity of skin alterations resulting from an immune reaction to progesterone. It is present under variable clinical aspects. A series of other recurrent skin conditions are not specifically induced but are merely exacerbated at the end of the ovarian cycle.

Laddering melanotic pattern of Langer's lines in skin of colour.

Mechanobiological stimulation of the skin influences melanocyte activity. The clinical impact on melanocytes can be perceived by dermoscopy. Our aim was to assess the orientation of Langer's lines using the combination of ultrasound shear wave propagation and dermoscopy in 70 adults of darker skin complexion. On the back, 44/70 patients showed a honeycomb melanotic pattern without any main orientation. By contrast, a streaky parallel pattern of melanotic lines oriented in the direction of Langer's lines was found in 26/70 patients. Indeed, the maximum speed of ultrasound propagation was found parallel to the main orientation of the laddering melanotic pattern. The parallel melanotic pattern probably reflects the main orientation of the epidermal rete ridges aligned in the direction of Langer's lines. This aspect could be ascribed to the deepening of these structures and/or to mechanobiology affecting melanocytes. The aspect is reminiscent of that previously described in striae distensae and atrophic scars.

Erlotinib-responsive actinic keratoses.

Erlotinib is an inhibitor of the tyrosine-kinase domain of the epidermal growth factor receptor-1 (EGFR). This drug is used to treat some solid cancers, particularly advanced non-small-cell lung carcinoma. Similar to other EGFR inhibitors, erlotinib is responsible for a series of skin adverse reactions, particularly acneiform lesions. We described the incidental effect of erlotinib on actinic keratoses which became markedly inflamed and showed partial regression. Inflammation appeared to spontaneously decrease while on erlotinib treatment. This reaction in the skin neoplasm is perhaps a visible and accessible model for predicting the effect in the deep-seated neoplasm targeted by the drug.

Mechanobiology and force transduction in scars developed in darker skin types.

BACKGROUND: Scarring is a complex process involving many cell types, cytokines and biological pathways including mechanobiology. Some subtle mechanical properties of skin can be assessed by measuring the speed of ultrasound shear wave propagation. The orientation of abnormal skin tension forces can be visualized, particularly in darker skin types, using dermoscopy showing distinct patterns of rete ridges' conformation. AIM: To assess some mechanobiological features of scars in darker skin types. PATIENTS AND METHODS: Large atrophic and hypertrophic surgical scars were examined on the trunk of 35 darker skin subjects. The surrounding skin was used as a comparator. Dermoscopic aspects were recorded. Resonance running time measurements (RRTM) were performed using a shear wave propagation device (Reviscometer). They were performed in four specific directions at given angles with regard to the long axis of the scar. The minimum, maximum and mean RRTM values were recorded at each site. RESULTS: Dermoscopy revealed patterns of melanin deposits in scars distinct from the normal honeycomb network seen in the surrounding skin. Hypertrophic scars showed a patchy pattern of large macular melanoderma dispersed in a lighter background. In these cases, low RRTM values were obtained with little variations according to the orientation of the measurements. By contrast, atrophic scars showed a streaky laddering melanotic pattern under dermoscopy. Higher RRTM values were often obtained, particularly in the transversal direction of the scars. Mechanical anisotropy was greater in the atrophic scars compared with the normal skin. DISCUSSION: Darker skin types represent a model for visualizing the main orientation of the epidermal rete ridges. A correlation was found between the pattern of melanized rete ridges of scars and the main orientation of the intrinsic forces in the skin.

Highlighting the rim of the perifollicular epidermal unit.

The perifollicular and interfollicular areas of normal skin may look similar. However, some physiological and pathological processes may specifically involve a thin perifollicular rim. This review illustrates some of the methods available for highlighting the rim of the perifollicular epidermal unit. Non invasive methods rely on dermoscopy, ultraviolet light enhanced visualization (ULEV), skin capacitance imaging and cyanoacrylate skin surface strippings (CSSS). Conventional histology and immunohistochemistry may also show specific perifollicular features without, however, revealing the aspects highlighted by the specific non invasive methods. The clinically relevant modifications consist of pigmentary and hyperkeratotic perifollicular changes.

Juvenile acanthosis nigricans and insulin resistance.

Acanthosis nigricans in obese adolescents is frequently associated with hyperinsulinemia and insulin resistance. We report three cases of this condition. In the early stage the skin lesions appeared to be erythematous and pruritic, mimicking an inflammatory dermatitis. Dietary control and oral metformin hydrochloride markedly improved the lesions. Topical calcipotriol may also help to control the skin condition.