SAPHO syndrome
Overview
SAPHO syndrome is a chronic disorder that involves the skin, bone, and joints. SAPHO is an eponym for the combination of synovitis, acne, pustulosis, hyperostosis, and osteitis. Synovitis means inflammation of the joint lining (synovium). Typically, this is manifests as warmth, tenderness, pain, swelling, and stiffness of involved joints (arthritis). Acne is a skin condition featuring tiny areas of inflammation with pus formation at the hair follicles. Acne occurs most commonly on the face and upper back. Pustulosis is a very inflammatory skin condition resulting in large fluid-filled blister-like areas (pustules), typically on the palms of the hands and/or the soles of the feet. The skin of these areas peels and flakes (exfoliates). Hyperostosis means abnormal excessive growth of bone. The hyperostosis of the SAPHO syndrome frequently is located at the points of the bone where tendons attach. Osteitis means inflammation of the bone. Patients with SAPHO syndrome can develop inflammation of the sacroiliac joints (sacroiliitis) as well as inflammation of the spine (spondylitis) which leads to stiffness and pain of the neck and back.
Symptoms
* Acne conglobata * Acne fulminans * Hydradenitis suppurativa * Exfoliating pustules on palms * Exfoliating pustules on soles * Sterno-costo-clavicular hyperostosis * Chronic osteomyelitis * Spondyloarthropathy * Skin lesions * Inflammation of joint lining * Sacroilitis syndesmophytes * Anterior chest lesions * Excessive localized bone growth - usually where bones and tendons attach * Oligoarthritis * Inflammation of spine * Inflammation of sacroiliac joints * Stiff neck * Stiff back * Neck pain * Back pain
Causes
The cause of acne is multifactorial, but theories regarding dietary influences appear to be groundless. Predisposing factors include heredity; hormonal contraceptives (many females experience an acne flare-up during their first few menstrual cycles after starting or discontinuing hormonal contraceptives); androgen stimulation; certain drugs, including corticosteroids, corticotropin, androgens, iodides, bromides, trimethadione, phenytoin, isoniazid, lithium, and halothane; cobalt irradiation; and hyperalimentation. Other possible factors are exposure to heavy oils, greases, or tars; trauma or rubbing from tight clothing; cosmetics; emotional stress; and unfavorable climate. More is known about the pathogenesis of acne. (See What happens in acne.) Androgens stimulate sebaceous gland growth and production of sebum, which is secreted into dilated hair follicles that contain bacteria. The bacteria, usually Propionibacterium acnes and Staphylococcus epidermidis (which are normal skin flora), secrete lipase. This enzyme interacts with sebum to produce free fatty acids, which provoke inflammation. Also, the hair follicles produce more keratin, which joins with the sebum to form a plug in the dilated follicle. Acne vulgaris primarily affects adolescents (usually between ages 15 and 18), although lesions can appear as early as age 8. Although acne strikes boys more often and more severely than girls, it usually occurs in girls at an earlier age and tends to last longer, sometimes into adulthood.
Prognosis
Prognosis of SAPHO syndrome: prolonged unpredictable course
Treatment
Treatment of patients with SAPHO syndrome is directed toward the individual symptoms that are present. Generally, treatment involves medications that reduce inflammation in the particular tissues affected. Examples of medications that are used for inflammation include nonsteroidal antiinflammatory drugs (NSAIDs, such as aspirin, ibuprofen, and naproxen) and cortisone medications (either in the form of topical creams, tablets, or by injection into the involved area). Topical cold applications can also help reduce inflammation in some tissues. For patients with persisting joint symptoms, both sulfasalazine and methotrexate have been tried with varying degrees of success.