Senile (solar) comedones

Favre-Racouchot disease: protective effect of solar elastosis

Favre-Racouchot disease (FRD) is an occupational disorder characterized by solar elastosis with open and cystically dilated comedones that tend to appear on the periorbital and temporal face of elderly light-complexioned men. It is a benign condition caused by chronic excessive ultraviolet exposure, as well as ionizing radiation and/or smoking. However, malignant skin neoplasms are uncommonly observed arising in FRD, which suggests a protective role of some element of FRD against carcinogenesis. We explore elastosis as a possibly beneficial tissue response. The clinical manifestations, pathogenesis, and recommended treatment options of this disorder are reviewed.

Application of ultrasound-mediated adapalene-coated lysozyme-shelled microbubbles in UVA-induced skin photoaging

Photoaging, the premature aging of skin induced by ultraviolet rays, is characterized by wrinkling, roughness, laxity, and pigmentary changes. Various natural and synthetic retinoids have been explored for the treatment of aging. Among retinoids, adapalene (Ada, 0.3%) is one of the most potent and widely used drugs to treat photoaging. However, it causes irritant reactions that limit its acceptance by patients. Several studies have shown the applicability of Lysozyme (Lys)-shelled microbubbles (MBs) for drug delivery through sonophoresis, and recently we have shown its efficiency to treat inflammatory skin disease. Here, we report the construction of novel Ada-LysMBs based on opposite electric charges for combined effects to treat photoaging. The Ada-LysMBs were self-assembled and had a mean diameter of 2857 nm. The maximum loading efficiency of Ada onto LysMBs was 13.99 ± 0.59%. An acoustic power density of 3 W/cm2 for 1 min revealing maximum penetration depth of LysMBs was optimized for further in vitro and in vivo studies of Ada-LysMBs. It was observed that in vitro Ada release from Ada-LysMBs at 6 h after ultrasound (US) treatment was more rapid at pH 7.4 (82%) than at pH 5.5 (73%). Franz diffusion experiments on isolated porcine skin indicated that US approximately doubled Ada delivery by Ada-LysMBs and Ada + LysMBs at 12 h and six-fold Lys permeation by LysMBs at 6 h, compared to these treatments alone. A 5-week in vivo study in mice identified significant wrinkle reduction in animals treated with US plus Ada-LysMBs. Our findings indicate that US may be used with Ada-LysMBs in the water phase to treat photoaging by normalizing hyperkeratinization and promoting collagen synthesis.

Suppressive oligodeoxynucleotides inhibit silica-induced pulmonary inflammation

Inhalation of silica-containing dust particles induces silicosis, an inflammatory disease of the lungs characterized by the infiltration of macrophages and neutrophils into the lungs and the production of proinflammatory cytokines, chemokines, and reactive oxygen species (ROS). Synthetic oligodeoxynucleotides (ODN) expressing "immunosuppressive motifs" were recently shown to block pathologic inflammatory reactions in murine models of autoimmune disease. Based on those findings, the potential of suppressive ODN to prevent acute murine silicosis was examined. In vitro studies indicate that suppressive ODN blunt silica-induced macrophage toxicity. This effect was associated with a reduction in ROS production and p47phox expression (a subunit of NADPH oxidase key to ROS generation). In vivo studies show that pretreatment with suppressive (but not control) ODN reduces silica-dependent pulmonary inflammation, as manifest by fewer infiltrating cells, less cytokine/chemokine production, and lower levels of ROS (p < 0.01 for all parameters). Treatment with suppressive ODN also reduced disease severity and improved the survival (p < 0.05) of mice exposed to silica.

Open comedones overlying granuloma annulare in a photoexposed area

A 57-year-old, fair-skinned female patient with lesions of granuloma annulare located on her forearms - with signs of actinic damage - is described. No response was observed after successive treatments with topical corticosteroids and oral pentoxifylline. Four years later, the patient developed open comedones on the rim of granuloma annulare lesions. The loss of elastic fibers seen in both granuloma annulare and solar elastosis is presumed to have induced the appearance of open comedones, because of a loss of supporting properties of the dermis inducing a distension of the infundibular canal of the sebaceous follicle, as seen in the Favre-Racouchot disease and actinic comedonal plaque. Concomitantly, the patient developed insulin-dependent diabetes mellitus. Treatment with insulin resulted in the disappearance of open comedones and notably regression of lesions of granuloma annulare. Response to insulin therapy in our case supports the hypothesis that insulinopenia could participate in the development of granuloma annulare in some cases.

Favre-Racouchot disease

Solar elastosis with comedones studding the central face is often referred to as Favre-Racouchot disease. These open and cystically dilated comedones tend to appear in the periorbital region of the face. The clinical manifestations, pathogenesis and current treatment of this disorder are reviewed.

[Autoradiographic investigations in actinic (senile) comedones (author's transl]

Skin specimens of patients suffering from actinic comedones, young patients with acne vulgaris, and normal controls of the same age groups respectively were subjected to in vitro autoradiography. From the results it can be concluded, that a rise in the proliferational activity in the follicular infundibulum due to actinic stimuli is responsible for the development and growth of actinic comedones.