Project Summary/Abstract In this application, we request funding for a one day symposium to provide an intense, high level, interactive symposium focusing entirely on Hidradenitis Suppurtiva (HS) or Acne Inversa, a dermatological disorder that results in recurrent inflammation in apocrine bearing skin and which affects approximately 1% of the population. World leaders in clinical and research dermatology will present their work and work together to define a current consensus on the clinical and diagnostic features of HS, best treatment options currently available, and the latest research focused on defining the pathogenesis and genetic basis for this physically and psychologically debilitating disease. The symposium will also provide a broad overview of basic and applied research currently underway that will be useful for practicing dermatologists. By keeping the meeting intimate and interactive, with speakers staying throughout the meeting, national and international networks based on respect and familiarity will develop amongst the group, as was the case following the First International HS Research Symposium in 2006. By holding the meeting in San Francisco one day prior to the start of the Annual Meeting of the American Academy of Dermatology (AAD), we will be able to minimize total symposium costs while maximizing attendance, which is critical in creating greater awareness for this under-recognized and poorly understood disease. The Symposium will take place on March 5, 2009 at a hotel conveniently located near the Moscone Center, the main site of the AAD meeting. The involvement of women and underrepresented minorities will be actively encouraged, and the editor of the home journal of the Hidradenitis Suppurativa Foundation Inc., "Experimental Dermatology" has agreed to publish symposium proceedings in a special report, free of charge in a future 2009 issue. Post-symposium surveys to all attendees will also be distributed to quantify results. PUBLIC HEALTH RELEVANCE: Relevance to Public Health This meeting has direct relevance to human health in that it is an effort to better characterize and understand Hidradenitis Suppurativa (HS), a poorly understood, debilitating inflammatory skin disease that affects an estimated 1% of the population and which is often characterized as an "orphan" disease. The main features of HS include painful and chronically recurring, deep-seated follicular nodules, papules, pustules and abscesses, scarring, sinus tracts and recurrent discharge. The areas most commonly affected are under the arms, groin, buttocks, and under the breasts. The disease is variable and recurrent. It may present with solitary or multiple lesions in one area, with lesions in many areas, or in more severe cases may have large areas of skin affected by recurrent, draining lesions that are difficult to heal. The diagnosis of HS is usually based on a clinical examination and a patient history. HS is therefore frequently misdiagnosed, and the time to accurate diagnosis may be measured in years, if not decades. These issues compound the high morbidity and disabling nature of the disease. Although a collaborative diagnostic methodology was published in 2000 specifically devised for a clinical investigation regarding the familial transfer of HS, there are no universally accepted diagnostic criteria for HS, which presents a significant challenge for patients, physicians, and researchers alike. Global consensus regarding diagnosis should be a priority in order to facilitate the advancement of HS research and to assist physicians in making more accurate and timely diagnoses. The wide, unpredictable and non-linear progression of HS may lead to significant long- term adverse effects on mental and physical health, severely reducing the quality of life. Those with HS often fail to receive appropriate, empathic recognition for a disease that is largely invisible, as it appears mostly in and around the intimate areas of their bodies. HS is difficult to live with as it is often resistant to therapy. Depression, frustration and anxiety are common, as is withdrawal from social, work and sexual relationships due to chronic pain, restricted mobility, persistent draining lesions and the need to frequently change clothes and dressings. Additionally, the economic impact of HS may be substantial. Even in mild to moderate HS, time off from work has been estimated to be up to 50% higher than average, and sometimes it is difficult for patients to maintain employment. Severe HS may also lead to temporary or permanent disability. Health insurance is often inadequate or unavailable, which adds to the financial burden of the disease. Experimental treatment with biologics holds promise, but the treatments are expensive and insurance approval continues to remain problematic. The gold standard for treating HS that is non-responsive to topical and systemic treatments is radical surgery with hospitalization, home care, extended wound care management and long recovery times, with a relatively high risk for infection and recurrence at the surgical site or other non-surgical areas. Recent research also indicates that long standing HS in non-axillary areas is a pre-malignant condition of squamous cell carcinoma (SCC) which often presents late and results in death, highlighting another significant reason for the urgent necessity for increased clinical awareness and research.