Diagnosing the SAPHO syndrome: a report of three cases and review of literature

Abstract

SAPHO, an acronym for synovitis, acne, pustulosis, hyperostosis and osteitis, is a heterogeneous entity with myriad presentations and features overlapping with other entities. It is a differential in patients presenting with skin and bone symptoms, either singly or in combination. Often misdiagnosed radiologically as a malignancy or infection, the diagnosis is seldom thought of. We present three cases referred to us for evaluation of findings unrelated to the presenting symptoms. After evaluation, a (99)Tc bone scan was ordered, which showed the 'bull's head sign' in all the three cases, confirming the diagnosis. We review the literature for SAPHO. It has a few features which point to its diagnosis and can help us to distinguish it from other seronegative arthritis. The clinician should be aware of this entity and should not hesitate to order a (99)Tc bone scan. We conclude that SAPHO is not rare, but rather, it is underdiagnosed. High index of suspicion is necessary for diagnosis. A (99)Tc bone scan is diagnostic and should be ordered in patients having any of the presenting features of the syndrome. We put forward the suggestion of using (99)Tc bone scintigraphy to define a 'pre-MRI' stage of ankylosing spondylitis.

A 26-year-old Woman With Bilateral Leg Pain and Pruritus

“…In this case, given the patient's diffuse bone involvement and robust dermatologic findings, SAPHO syndrome was considered. Dermatologic findings of SAPHO syndrome appear as severe acne or pustules that most commonly present on the palms or soles [7,11]. However, our patient had excoriations secondary to pruritus but lacked acneiform lesions or palmoplantar pustulosis as typically would be seen with SAPHO syndrome.…”

“…However, our patient had excoriations secondary to pruritus but lacked acneiform lesions or palmoplantar pustulosis as typically would be seen with SAPHO syndrome. Additionally, pruritus has not been a common reported symptom of SAPHO syndrome [7,11]. Bone biopsy specimen in SAPHO syndrome often show remodeling and other reactive bone changes but lacks the aggregates of mast cells seen in our patient's bone biopsy specimen.…”

“…This rare condition often is unrecognized because of the wide variability in its musculoskeletal and cutaneous manifestations [11]. This condition has been described in the literature as chronic recurrent multifocal osteomyelitis (CRMO) and various other names [7,11]. In this case, given the patient's diffuse bone involvement and robust dermatologic findings, SAPHO syndrome was considered.…”

Osteomielitis crónica multifocal recurrente: estado del arte

“…Por lo general, afecta a niños y adolescentes, con una edad promedio de inicio de 10 años y predominantemente en el género femenino, aunque también hay reportes de adultos jóvenes. Puede haber una historia [32][33][34][35][36][37][38][39][40] familiar de enfermedades inflamatorias, pero únicamen-te en el 6% habrá un miembro con el diagnóstico de CRMO 1,2,4,12 .…”

“…Así, la pared anterior del tórax (articulación esternocostoclavicular) es el sitio más comúnmente afectado en adultos; mientras que el tercio medio de la clavícula es el sitio de mayor afectación en la población pediátrica. Por su parte, el esqueleto axial es el segundo sitio más [32][33][34][35][36][37][38][39][40] comprometido en ambos grupos, entre 32%-52% de los casos y el orden de compromiso en este segmento se da en la columna torácica, lumbar y cervical 8,9 .…”