Sapho syndromeM86.8

SAPHO is the acronym for:

• Synovitis
• Acne
• Pustulosis
• Hyperostosis
• Osteitis.

Clinically multifaceted autoinflammatory skin-bone-associative syndrome (SkoBo) occurring in all age groups with a mostly recurrent , subacute to chronic course. The most common partial manifestation of the syndrome is chronic, recurrent (non-bacterial) multifocal osteomyelitis, which may also involve adjacent joints. Comorbid, landmark, dermatologic monitor symptoms in this case are the following neutrophilic dermatoses:

• Pustulosis palmaris et plantaris
• Psoriasis palmaris et plantaris
• Acne conglobata/Acnefulminans
• Hidradenitis suppurativa
• Sweet syndrome
• Pyoderma gangraenosum (Vekic DA et al 2018).

SAPHO syndrome is also referred to as "skibo-disease" ("skin and bone disease") to emphasize the characteristic association of pathologic osteoarticular and dermatologic symptoms.

The etiology of SAPHO syndrome is not fully understood. The osteo-articular disease processes include a probable reactive-immunologic (rheumatoid factor-negative), oligo- or polytopic, inflammatory but never septic (non-bacterial) process of the bone and adjacent joint structures with inflammatory enthesiopathies. A possible trigger function proceeds from skin infections, although intervals of one year may lie between the dermatological and osteo-articular manifestations .

The criteria for this syndrome are defined as sterile osteitis (blanched, non-bacterial osteomyelitis) including spondylitis and/or arthritis, which may occur with or without skin lesions. SAPHO is now more commonly understood as an umbrella syndrome and overarching term for a number of syndromes and disease entities, esp:

• Chronic recurrent multifocal osteomyelitis(CRMO= juvenile variant of SAPHO syndrome).
• Arthroosteitis, pustular (ACW syndrome /ACW = anterior chest wall syndrome/s.under Pustular arthroosteitis/Sonozaki syndrome)
• Arthritis and spondarthritis in pustular psoriasis
• Hyperostotic spondarthritis
• Acne spondarthritis

Within the umbrella syndrome SAPHO, various associations and overlaps are possible, with the cutaneous-osseous association not being an obligate but a characteristic phenomenon. Also described is an enteropathic variant of SAPHO syndrome that, in addition to the above symptoms, is associated with Crohn's disease or ulcerative colitis (approximately 5% of SAPHO patients (Naves JE et al. 2013). Of note and etiopathogenetic interest is the occurrence of SAPHO syndrome during isotretinoin therapy of acne fulminans (Luzzati M et al. 2020)

Autoantibodies were found in a larger SAPHO collective in about 22% of patients: 15.5%: positive ANA (titer >/= 1/160); antithyroid antibodies (anti-TPO and/or anti-Tg antibodies): Antibodies against gastric parietal cells: 3.3 %, antibodies against smooth muscle:4.4 %. Antimitochondrial and LKM antibodies: negative. Anti-CCP and anti-dsDNA antibodies: negative (Grosjean C et al. 2010). To what extent an etiopathogenetic significance must be attributed to them is open.

There are numerous, but not standardized, modalities of therapy.

• Initial: Non-steroidal anti-inflammatory drugs. If necessary, in the acute painful stage, systemic glucocorticoids in mttler dosage (e.g. prednisolone 50 mg/day p.o.), fumaric acid esters (with or without methotrexate; MTX dosage: 15-25 mg/week p.o.).
• Also effective are TNF-alpha blockers (e.g., infliximab or etanercept).
• Systemic antibiotics are usually ineffective.
• In elderly patients with significant osteopathic pain, bisphosphonates such as pamidronate (single application of 60 mg i.v. every 4 months) or zoledronic acid (single administration of 4 mg i.v.) have been used successfully.

SAPHO syndrome belongs to the extended group of so-called autoinflammatory diseases. Pathogenetically, a relationship or identity of the SAPHO syndrome with the pustular arthroosteitis described by Sonozaki and the chronic recurrent multifocal osteomyelitis (CRMO) of childhood is discussed. The sterno-costo-clavicular hyperostosis (ACW -so-called anterior chest wall syndrome) is a polyetiological, reactive symptom complex associated with pustulosis palmaris et plantaris on the skin.

1) Reported is the 8-year treatment course of a 40-year-old man with hidradenitis suppurativa and synovitis, acne, pustulosis palmaris et plantaris, hyperostosis, and osteitis syndrome. Initial oral and topical antibiotics had little effect. Intralesional corticosteroid injections were effective for localized inflammatory lesions but were not sufficient to control hidradenitis suppurativa. Introduction of adalimumab and local remediation of hidradenitis suppurativa resulted in stabilization. Adalimumab resulted in dramatic improvement in back pain. Continuation of treatment with adalimumab and subsequent administration of methotrexate resulted in extensive improvement of the clinical picture.

2) The case of a boy who suffered from acne fulminans and depression and developed sacroiliitis after 10 weeks of treatment with isotretinoin is presented. After SAPHO diagnosis, NSAID therapy was initiated, but the appearance of bilateral gluteal hidradenitis suppurativa required a switch to a TNF-alpha antagonist(adalimumab), with which good control of the disease was achieved. Despite specific therapy with sertraline, the patient continued to complain of severe depression (Luzzati M et al 2020).

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