What Is SAPHO Syndrome?

SAPHO syndrome is a chronic disease that mainly affects the skin, bones, and joints. SAPHO is the abbreviation of the following 5 English words, namely: synovitis, acne, pustulosis, hyperostosis, and osteomyelitis.

Basic Information

nickname: Synovitis-acne-pustular disease-bone hypertrophy-osteomyelitis syndrome
English name: SAPHO Syndrome
English alias: synovitis-acne-pustulosis-hyperostosisosteomyelitis syndrome

Visiting department: orthopedics
Multiple groups: European youth and middle-aged
Common locations: Skin, bones and joints
Common symptoms: Bone and joint swelling and pain, inflammation around the joints, palmoplantar pyoderma, acne, psoriasis, etc.

Causes of SAPHO syndrome

The etiology of this disease is unknown. There are several hypotheses:

1. Circulating immune complex The circulating immune complex was found in fulminant acne, which may be the result of the immune response to P. acnes. These immune complexes cause inflammatory processes in the bone, leading to clinical osteolytic damage.

2. Environmental factors Palmoplantar pustulosis has a high incidence in some areas and is considered to be related to environmental factors.

3. About 1/3 of the patients are HLA-B27 positive. In the family of patients with SAPHO syndrome, 14% have palmoplantar pyoderma, 19% have psoriasis, and 5% have acne.

Clinical manifestations of SAPHO syndrome

The age of onset is more frequent in youth and middle age. The youngest age is 10 years old and the oldest is 59 years old. Male to female ratios vary. Patients often have bone and joint swelling and pain. The most commonly affected are the sternoclavicular joint, sternoclavicular joint, shoulder joint, sacrum, and pubic bone. Most patients have more than two lesions and can be accompanied by inflammation around the joints. Half of the patients have palmoplantar pyoderma, and a few have acne and psoriasis.

The main symptoms are pain and swelling of the anterior chest wall, which is often bilateral, and worsens when the weather is humid and cold. After a long course of sternum and clavicle junction fusion, bone hypertrophy can compress adjacent nerve vessels.

Bone lesions can also occur in the spine, long bones, sacrum, mandible and pubic bone. The damage often begins at the attachment of tendons and ligaments, and both of them also have bone hypertrophy and often arthritis, especially sacroiliitis. Skin damage can manifest as palmoplantar pustulosis, purulent sweat glanditis, or severe acne.

SAPHO syndrome test

1. C-reactive protein increased and rheumatoid factor was negative. The white blood cell count and blood cell count increased, ANA was positive, and HLA-B27 was about 30% positive.

2. X-ray examination: there is no obvious change in the early stage. With the progress of the disease, irregular infiltration of the sternoclavicular joint and sternocostal joint can be seen, and the cortical hypertrophy. It can also involve the wrist joint, neck, chest, waist, and iliac crests, showing diffuse hyperplasia of adjacent 2 to 4 vertebrae. Sacroiliac joint lesions are often asymmetric.

SAPHO syndrome diagnosis

According to symptoms, signs, typical synovitis, acne, impetigo, bone hypertrophy, osteomyelitis and other manifestations, the disease is not difficult to diagnose.

Differential diagnosis of SAPHO syndrome

Should be distinguished from psoriatic arthritis, ankylosing spondylitis, Rett syndrome, and sclerosing osteomyelitis. Some people think that although spinal joint disease has many similarities with SAPHO syndrome, the two should be distinguished. SAPHO syndrome is manifested as osteitis and sclerosis, rather than real arthritis. Sacral arthritis is about 50% unilateral in SAPHO syndrome and usually bilateral in spinal arthropathy. Osteomyelitis is common in SAPHO syndrome and uncommon in spinal arthropathy.

SAPHO syndrome complications

May be complicated by sternocele arthritis, sternocostal arthritis, sacroiliitis, psoriasis.

SAPHO syndrome treatment

Due to the relatively benign course of the disease and its unknown cause, the current treatment is mainly symptomatic, and nonsteroidal drugs are preferred. Some patients with severe inflammatory reactions and non-steroidal drugs with insignificant curative effects can use short- and medium-dose corticosteroids for short-term peripheral synovitis or obvious lesions. Try methotrexate, and those with inflammatory bowel disease can try Sulfasalazine (sulfasalazine).

Recent research shows that a new generation of bisphosphonates, pamidronate, is effective for the treatment of this disease. Oral pamidronate is generally administered for about 6 months, which can effectively relieve symptoms.