Dear Editor,
Arthritis of the first metatarsophalangeal (MTP) joint of a different cause than gout is identified by the term pseudopodagra. Although the majority causes of pseudopodagra are deposits of other micro crystals, there has been other rare cause, such as Behcet's disease.11. Benamour S. Pseudopodagra in Behçet's disease. Rev Rhum Engl Ed 1995;62: 2153-4.,22. Giacomello A, Sorgi ML, Zoppini A. Pseudopodagra in Behçet's syndrome. Arthritis Rheum 1981; 24: 5750-1. We present the case of a patient with a pseudopodagra due to Behcet's disease.
A 43-year-old female patient suffering from Behcet's disease for 10 years presented to
the emergency department (ED) with discomfort in her right MTP joint. The onset was
characterized by acute pain, swelling, erythema, tenderness, and limitation of movement
of the first MTP joint of the right foot. The patient denied any fever, chills, trauma,
urethral symptoms, conjunctivitis, or history of gout. She had a past several attacks
affecting oligoarticular involving knees and ankles. There was no family history of
rheumatic disease. On physical examination, she was afebrile and all vital signs were
normal. The area overlying her first MTP joint was red, hot, swollen, and exquisitely
tender to touch and to any movement of the great toe.The skin was not disrupted, and no
lymphangitis or adenopathy was present. All other joints were normal, as was the
remainder of the physical examination. Patient refused arthrocentesis procedure. We
preferred ultrasound imaging as a first line imaging technique instead of magnetic
resonance imaging in order to save time. Grayscale ultrasound examination of dorsal
aspect of 1st MTP showed marked synovial thickening (arrows) and minimal synovial fluid
(arrowhead) (Fig. 1 A). There was no
gouty tophus at the MTP joint. On power doppler imaging increased color signals are seen
within the hyperthrophic synovium consistent with hyperemia (Fig. 1B). On left side, minimal concentric
proliferation of synovial lining cell tissue and synovial fluid (arrowhead) was seen
(Fig. 2A). There were no color
signals within the synovium on the 1st MTP of the left foot ( Fig. 2B). Preliminary diagnosis was pseudopodagra
rather than metatarsophalangeal arthritis because significant extra-articular soft
tissue changes were evident. Soft tissue changes can occur with rheumatological diseases
including familial Mediterranean fever (FMF)'s joint attack, acute rheumatic fever
(ARF), calcium pyrophosphate dihydrate (CPPD) crystal deposition disease and gout.
Rheumatoid arthritis also commonly affects the MTP joints, although this is
characterized with a symmetric polyarthritis, making it a rare differential diagnosis.
In our patient FMF and ARF were not considered as a relevant differential diagnosis
because those diseases were inconsistent with clinical and laboratory findings.
Sonographic features of CPPD deposits depend on the amount and distribution, varying
from homogeneously punctate pattern or sharply defined hyperechoic bands within the
articular cartilage or floating in synovial fluid to rounded or amorphous-shaped
hyperechoic areas in fibrocartilage.33. Lin YY, Wang TG, Li KJ, Lew HL. Imaging Characteristics of Calcium
Pyrophosphate Dihydrate Crystal Deposition Disease. Am J Phys Med Rehabil 2012;
Http://dx.doi.org/10.1097/PHM.0b013e31825566aa.
Http://dx.doi.org/10.1097/PHM.0b013e3182...
In the
gout, monosodium urate crystals tend to result in hyperechoic enhancement on the
superficial margin of hyaline cartilage. The most frequent ultrasonographic
characteristic of gouty tophi is hyperechogenicity.44. Fernandes EA, Lopes MG, Mitraud SA, Ferrari AJ, Fernandes AR.
Ultrasound characteristics of gouty tophi in the olecranon bursa and evaluation of
their reproducibility. Eur J Radiol 2012; 81: 2317-23. In addition, tophi are generally heterogeneous, with poorly defined
contours, multiple grouped and surrounded by an anechoic halo.55. de Ávila Fernandes E. Kubota ES. Sandim GB. Mitraud SA. Ferrari AJ.
Fernandes AR. Ultrasound features of tophi in chronic tophaceous gout. Skeletal
Radiol 2011;40:3309-15.,66. de Ávila Fernandes E. Sandim GB. Mitraud SA. Kubota ES. Ferrari AJ.
Fernandes AR. Sonographic description and classification of tendinous involvement in
relation to tophi in chronic tophaceous gout. Insights Imaging 2010;
1:3143-8. However, these
sonographic findings were not seen in our patient.
A, Grayscale ultrasound examination of dorsal aspect. B, Power doppler imaging increased color signals.
A, Minimal concentric proliferation of synovial lining cell tissue and synovial fl uid. B, There were no color signals within the synovium.
Musculoskeletal ultrasound has significant potential usefulness for the diagnosis, severity assessment, decision to treat, and treatment efficacy assessment of patients with unknown etiology arthritis.77. Howard RG, Pillinger MH, Gyftopoulos S, Thiele RG, Swearingen CJ, Samuels J. Reproducibility of musculoskeletal ultrasound for determining monosodium urate deposition: concordance between readers. Arthritis Care Res (Hoboken):2011;63:101456-62. The ultrasound examination as a fast, reproducible diagnostic method has now become part of the routine diagnosis in rheumatological disorders.
REFERÊNCIAS
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1Benamour S. Pseudopodagra in Behçet's disease. Rev Rhum Engl Ed 1995;62: 2153-4.
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2Giacomello A, Sorgi ML, Zoppini A. Pseudopodagra in Behçet's syndrome. Arthritis Rheum 1981; 24: 5750-1.
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3Lin YY, Wang TG, Li KJ, Lew HL. Imaging Characteristics of Calcium Pyrophosphate Dihydrate Crystal Deposition Disease. Am J Phys Med Rehabil 2012; Http://dx.doi.org/10.1097/PHM.0b013e31825566aa.
» Http://dx.doi.org/10.1097/PHM.0b013e31825566aa -
4Fernandes EA, Lopes MG, Mitraud SA, Ferrari AJ, Fernandes AR. Ultrasound characteristics of gouty tophi in the olecranon bursa and evaluation of their reproducibility. Eur J Radiol 2012; 81: 2317-23.
-
5de Ávila Fernandes E. Kubota ES. Sandim GB. Mitraud SA. Ferrari AJ. Fernandes AR. Ultrasound features of tophi in chronic tophaceous gout. Skeletal Radiol 2011;40:3309-15.
-
6de Ávila Fernandes E. Sandim GB. Mitraud SA. Kubota ES. Ferrari AJ. Fernandes AR. Sonographic description and classification of tendinous involvement in relation to tophi in chronic tophaceous gout. Insights Imaging 2010; 1:3143-8.
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7Howard RG, Pillinger MH, Gyftopoulos S, Thiele RG, Swearingen CJ, Samuels J. Reproducibility of musculoskeletal ultrasound for determining monosodium urate deposition: concordance between readers. Arthritis Care Res (Hoboken):2011;63:101456-62.
Publication Dates
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Publication in this collection
Jan-Feb 2014