Dysfunction in the PI3K pathway causes a spectrum of related megalencephaly syndromes.A number of overgrowth syndromes affecting tissues of multiple lineages have been linked to specific mutations that can occur postzygotically and involve only diseased tissue. Investigators of two recent studies examined the overgrowth syndromes that affect the brain. Megalencephaly-capillary malformation (MCAP) is associated with skeletal overgrowth and vascular malformations that meet criteria for Klippel-Trenaunay syndrome; hemimegalencephaly (HME) is associated with hypomelanosis of Ito and Proteus syndrome.
Inflammatory Reactions of Molluscum Contagiosum in Children
Inflammatory reactions are common in this self-limited viral skin infection.Molluscum contagiosum (MC) is a common, self-limited viral skin infection occurring in about 20% of healthy children. Resolution occurs within a few months to a few years. Inflammatory reactions are poorly studied, but they are common, often causing pruritus, pain, and sometimes confusion with bacterial superinfection.
These findings may explain why treatments are effective in some, but not all, vitiligo patients.Vitiligo is an acquired depigmenting disorder of uncertain etiology. Anecdotal reports imply that the disease responds to topical vitamin D analogs, suggesting that vitamin D may be involved in its pathogenesis. To investigate the relationship between vitamin D and vitiligo, investigators in China looked at polymorphisms in vitamin D receptor genes in 749 vitiligo patients and 763 control subjects.
Oral Corticosteroids Do Not Increase the Incidence of Nonmelanoma Skin Cancers
Skin cancer is one of the few effects that physicians do not have to worry about in long-term systemic corticosteroid users.Oral corticosteroids are potent anti-inflammatory and immunosuppressive agents that are effective for a wide variety of conditions. Other immunosuppressive agents, such as azathioprine and cyclosporine, have been found to augment risk for nonmelanoma skin cancers, particularly squamous cell carcinoma (SCC). Despite widespread use over decades, the extent to which long-term oral corticosteroid treatment increases skin cancer risk is uncertain. To examine this issue, researchers analyzed data from the Veterans Affairs Topical Tretinoin Chemoprevention Trial. Subjects were veterans at high risk for nonmelanoma skin cancers; organ transplant recipients were excluded. The authors compared development of new SCCs or basal cell carcinomas (BCCs) in 148 patients who filled prescriptions for prednisone and 903 who did not. The mean duration of prednisone therapy was 190.5 days, with a median of 21 days. The mean cumulative dose was 372 mg when prednisone was taken for less than 1 month and 4555 mg when treatment was longer than a month. Median follow up was 3.4 years.
Fibroblastic Connective Tissue Nevus: A New Type of Dermal Fibroblastic/Myofibroblastic Lesion
CD34 positivity can help to confirm this diagnosis.
Dermal fibroblastic/myofibroblastic proliferation characterizes a range of lesions with a common lineage but differing histology, clinical context, and behavior. Connective tissue nevus (CTN) is one such lesion; it can occur sporadically or associated with syndromes such as storiform collagenoma associated with Cowden syndrome. These authors analyzed the clinicopathologic presentation of a new CTN variant they call fibroblastic connective tissue nevus (FCTN).
An analysis of 53 studies suggests higher prevalence north of the equator, in lighter-skinned populations, and in older people.
Genetic and environmental factors contribute to the complex pathogenesis of psoriasis. To better understand the burden of psoriasis worldwide, these researchers conducted a systematic review of the published literature, with an eye to how variables such as geographic location, gender, and age affect incidence and prevalence, and how variations in study design and definition of cases and prevalence affect epidemiology of the disease. They limited their analysis to rates in the general population, including 46 studies examining prevalence and 7 evaluating incidence.
In a small case series, this oral anticoagulant reduced the number of new ulcerations and decreased pain.
Livedoid vasculopathy is a chronic, often painful eruption of recurrent, small ulcerations, usually affecting the lower legs. This condition has been linked to a variety of coagulopathies, but even in the absence of an identifiable genetic clotting abnormality, the disease is characterized by observation of thrombotic plugging of the small vessels in skin biopsy samples. Therapy is aimed at lowering thrombophilic potential in affected patients. Rivaroxaban is a newly approved oral anticoagulant used for the prevention of thromboembolism. It blocks factor Xa and causes an irreversible inhibition of thrombin formation and the development of thrombi. It has no effect on platelets.
Leukotriene B4: A Central Recruiter of Neutrophils in Allergic Dermatitis
LTB4-mediated attraction of neutrophils to skin subjected to tape stripping, a surrogate for scratching, is essential for development of allergic inflammation.
The itch–scratch cycle is a key component of exacerbations of atopic dermatitis (AD). Influx of T cells, particularly T helper 2 (Th2) cells, with eosinophils, has long been known to play a role in AD. Oyoshi and colleagues found a surprising new player.
Adalimumab a "Proven" Therapy for Hidradenitis Suppurativa
Weekly treatment produced a small but statistically significant improvement in moderate to severe disease.
Disruptions of both innate and acquired immune regulation can influence the development of psoriasis.
Psoriasis is well known to have a critically important immune component. Many genome-wide association studies (GWAS) of psoriasis have identified genes involved in epidermal development and immune regulation. Tsoi and colleagues performed a meta-analysis of three GWAS and two independent data sets of genotyped individuals, with a focus on areas of the genome known to be important for immune function.