Acquired immunologicaL LOw prevalence and Complex AdulT diseases of thE SKIN (ALLOCATE SKIN)


The following conditions are the main focus of the Thematic Group Hidradenitis suppurativa & related syndromes.

Hidradenitis Suppurativa

Hidradenitis Suppurativa or Verneuil’s disease is a common disorder, particularly in women.It is characterised by painful nodules, abscesses, fistulas and hypertrophic “bridged” scarring in apocrine gland-bearing areas of the body, mainly the deep folds of the axillary, inguinal and anogenital regions. It is a chronic disease.Smoking is thought to be a trigger although there is no evidence to suggest it is a risk factor; being overweight appears likely to be a risk factor although the aetiology has not yet been elucidated: this is a hair follicle disorder that is neither infectious nor hormonal in origin. The serious, dramatic forms are not the most common. Impact on quality of life is severe even with the moderate forms. Treatment is both medical AND surgical, involving broad spectrum antibiotics and surgical removal of the affected area.

Thérapeutique Dermatologique

SAPHO syndrome

SAPHO syndrome (acronym for Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) is an auto-inflammatory disease, mainly characterized by the association of neutrophilic cutaneous involvement and chronic osteomyelitis.
The age of onset ranges from childhood to late adulthood, with a median age between 30 and 40 years. SAPHO syndrome encompasses a wide spectrum of anomalies characterized by variable combinations of osteoarticular and cutaneous manifestations of varying degrees of severity. The onset of bone and joint pain, stiffness and swelling is most often insidious. In adults, inflammation occurs mainly in the anterior chest wall but also in the spine, less frequently in the mandible and the iliac bones ; in children it shows a comparable distribution as chronic non bacterial osteomyelitis (CNO/CRMO) (e.g. long bones, clavicle, spine). When synovitis occurs, it manifests most of the times in the sacro-iliac joint, hips or knees, or the sternoclavicular joints. Depending on severity of symptoms, a limited range of motion may be observed. Dermatological involvement includes severe acne, palmoplantar pustulosis, and pustular psoriasis. Skin manifestations often begin 1-2 years before osseous changes but may appear simultaneously or more than 20 years later. Patients may also suffer from abdominal pain, diarrhea, anal fissures or abscesses, suggesting the possible association with an inflammatory bowel disease (IBD). Most authors regard CNO/CRMO as the pediatric form of SAPHO syndrome. In fact, the frequent occurrence of dermatological disorders or IBD pleads for the inclusion of these two entities in the same spectrum.

PAPA syndrome

PAPA syndrome Pyogenic arthritis-pyoderma gangrenosum-acne syndrome is a rare pleiotropic autoinflammatory disorder of childhood, primarily affecting the joints and skin. The first affected family contained ten affected members from three generations and manifested variable expression of a pauciarticular, nonaxial, arthritis that began in childhood; pyoderma gangrenosum; and severe cystic acne in adolescence and beyond. PAPA syndrome is a self-limiting disease, but it can lead to severe joint destruction. Synovial fluid is purulent with neutrophil accumulation, but cultures are invariably negative. Recurrent sterile arthritis usually occurs after minor trauma, but can also occur spontaneously. Other less commonly associated features include adult-onset insulin-dependent diabetes mellitus, proteinuria, and abscess formation at the site of parenteral injections (pathergy). To date, only 34 patients with PAPA syndrome have been reported worldwide, from five families (two in the USA, one in Italy, one in the Netherlands, and one in New Zealand).

PASH Pyoderma gangrenosum-acne-suppurative hidradenitis syndrome

PASH Pyoderma gangrenosum-acne-suppurative hidradenitis syndrome is a rare skin disease belonging to the spectrum of autoinflammatory syndromes characterized by the triad of pyoderma gangrenosum (PG), suppurative hidradenitis (SH) and acne.

PAPASH syndrome

The PAPASH syndrome (pyogenic arthritis, pyoderma gangrenosum, acne, hidradenitis suppurativa / acne inversa) has recently been described in few unrelated patients as a new entity within the spectrum of hidradenitis suppurativa / acne inversa syndromes. PAPASH syndrome is similar to PAPA syndrome but differs insofar as it includes hidradenitis suppurativa / acne inversa. Mutations of the PSTPIP1 gene have been detected in some cases.

PASS syndrome

PASS syndrome is a rare inflammatory disease characterised by a chronic-relapsing course of pyoderma gangrenosum, acne vulgaris, hidradenitis suppurativa and ankylosing spondylitis.