pustulotic arthro - osteitis ( pao ) was first described by sonozaki.it is a relatively rare disease
a 53-year - old woman was admitted to our department in february 2007 with a pustular rash affecting the palms and soles .
inflammation and swelling of the small joints and right - sided low back pain developed during hospitalization .
the patient had no history of psoriasis and there was no history or clinical evidence of psoriasis in her family . on physical examination , sharply demarcated erythematosquamous lesions with groups of sterile pustules were seen on the palms and soles [ figures 1 and 2 ] .
there was diffuse swelling and erythema over the right sternoclavicular , the right wrist and the left ankle joints .
pustular lesions on the right palm pustular lesions on the medial sides of feet laboratory findings showed an erythrocyte sedimentation rate ( esr ) of 120 mm / h ( normal < 20 mm / h ) and c - reactive protein ( crp ) of 6.44 mg / dl ( normal<0.8 mg / dl ) .
serum was negative for rheumatoid factor and antinuclear factor , and anti - dsdna , anti - ro , anti - la , and anti - sm antibodies were not present .
a technetium-99 m diphosphonate - labeled scintigram of bones revealed abnormal focal increases in tracer uptake in the right sternoclavicular and left ankle joints [ figure 3 ] although x - ray of the wrist and the sternocostoclavicular region revealed soft tissue swelling , there was no ossification of the sternocostoclavicular region .
a computed tomography scan showed sclerosis of the sacroiliac joints whole - body bone scintigram skin biopsy from lesions on the left hand showed spongiosis and dyskeratotic cells in the basal layer , with infiltration of polymorphonuclear cells under the orthokeratotic epidermis .
a dense dermal neutrophilic infiltrate was also present . on the basis of these clinical and histopathologic features and the scintigram findings we made the diagnosis of pao .
after about 1 week of treatment , the swelling and pain in the affected joints had decreased , and the prednisone dose was tapered to 10 mg per day . during that time , new palmoplantar pustulotic lesions appeared .
the patient is now healthy after 6 months follow - up and no maintenance treatment is required .
palmoplantar pustulosis is a skin disease characterized by recurrent eruptions of sterile pustules , with erythema and exfoliation .
the lesions are situated exclusively , and often symmetrically , on the palms and/or soles.[13 ] the age of onset is usually 3060 years , and males and females are affected equally .
pao is a rheumatic syndrome of unknown etiology and is characterized by an inflamatory osteitis of the sternoclavicular joint along with palmoplantar pustulosis .
pao or sonozaki syndrome occurs in about 10%30% of patients with palmoplantar pustulosis . until a few years ago
, this syndrome was considered to be a manifestation of psoriatic arthritis and was then erroneously classified by rheumatologists in the sapho ( synovitis , acne , pustulosis , hyperostosis , osteitis ) syndrome .
similar clinical features have been observed in patients with sternocostoclavicular hyperostosis ( scch ) and sapho .
scch is a rare condition characterized radiologically by progressive hyperostosis of the medial ends of the clavicles , upper ribs , and sternum , together with soft tissue ossification between the upper ribs and clavicles .
clinically , the patients present with painful swelling of the sternum , clavicles , and upper ribs .
sapho presents with anterior chest wall involvement , axial skeletal lesions , and osteitis of appendicular bones .
pao is now classified as a member of the seronegative spondyloarthritis group of disease ( which includes ankylosing spondylitis , reiter 's syndrome , and psoriatic arthritis ) ; however , it is not associated with hla - b27 .
the principal lesion in pao is sternoclavicular involvement , with lesions also occurring in the spinal column and the sacroiliac and peripheral joints .
our patient had swelling of the sternoclavicular , right wrist , and left ankle joints , as well as low back pain .
although our patient had osteoarthritis affecting the sternoclavicular region , right wrist , and left ankle , as shown by the bone scan , there were no obvious radiological changes .
arthritis of the sternoclavicular joint is most frequent in patients with pao , but occurs in less than 15% of patients with ankylosing spondylitis , reiter 's disease , and psoriatic arthropathy.[68 ] in the majority of the cases , the arthritis is of seronegative mono- or oligo - arthritic type , as in our patient who had oligoarticular arthritis . in pao ,
the most commonly affected peripheral joints are the metacarpophalangeal joints , the proximal interphalangeal joints of fingers , and the elbow and knee joints .
other joints such as the hip , the ankle , and the wrist joints have also been involved rarely .
our patient had ankle and wrist arthritis , but the knee joint was not involved .
pao is characteristically non - erosive and transient and does not induce contracture deformities , and this was true in our patient also . the interval between the onset of skin eruptions to the onset of arthro - osteitis is about 2 years in more than 70% of cases . in our patient ,
the cause of these abnormalities , like the cause of the underlying disease process , remains unclear .
recently cultured propionibacterium acnes from biopsy specimens of patients with this syndrome in approximately 50% .
this agrees with the experience of other workers , who have also failed to isolate any specific microorganism from the bones or skin lesions of affected patients . in pao ,
the arthropathy is not associated with hla - b27 , and this was true in our patient also .
to the best of our knowledge , hla - b27 is related to generalized pustular psoriasis , psoriatic arthritis , ankylosing spondylitis , and reiter 's disease .
x - ray findings have been consistently reported to be negative , except for soft tissue swellings in acute phases , as in our patient also .
the presenting symptoms and findings in our patient , including palmoplantar pustulosis and arthro - osteitis , were compatible with sonozaki syndrome or pao .
treatment is usually symptomatic and consists mainly of analgesics and nonsteroidal anti - inflammatory drugs such as phenylbutazone and indomethacin .
corticosteroids , colchicine , sulfasalazine , methotrexate , and cyclosporine have been used with variable success .
topical steroids , etretinate , and topical puva have been used for the pustular lesions on the palms and soles . if the anterior chest wall symptoms are so severe as to interfere with the patient 's daily activities , surgical resection of the clavicle is recommended .
presented here , dapsone treatment was used successfully to treat the cutaneous manifestations and it also maintained the prolonged remission . to the best of our knowledge , this is the first report of pao from turkey .
radiological studies must be performed in a patient with palmoplantar pustulosis and swelling of joints to avoid missing the diagnosis .
 pustulotic arthro - osteitis , first described by sonozaki , is a relatively rare disorder . 
 its prevalence is however probably underestimated in dermatological literature . 
 early recognition of the signs can prevent misdiagnosis . 
 we describe a turkish patient who presented with palmoplantar pustulosis and involvement of the sternoclavicular joint and peripheral oligoarthritis . 
Introduction
Case Report
Discussion