SW$&§^&0&:%-#i$£V;

Psoriatic arthritis in severe Hugh Little, md,

frcp[c]; J. N. Harvie,

Summary: Of 100 patients admitted to hospital for treatment of psoriasis, 32 had clinical or radiologic evidence of psoriatic arthritis and 17 had both types of evidence. Eight had radiologic evidence of spinal or sacroiliac

md,

psoriasis

frcp[c], R. S. Lester, md, frcp[c]

Psoriasis is

a common

skin condition

affecting 1 to 2% of the population.1 The recognized extracutaneous compli¬ cations are psoriatic arthritis,2 hyperuricemia and gout.3 Psoriatic arthri¬ tis develops in an estimated 5 to 7% of patients with psoriasis.4 involvement without symptoms, and seven had clinical evidence of peripheral Joint lesions in psoriasis were first described in the French literature in arthritis without radiologic evidence. the early 19th century.6 In 1924 GarPatients with psoriatic sacroiliitis and rod and Evans5 described three patients spondylitis were most likely to have with psoriasis and arthritis and con¬ typical radiographic changes. It was cluded that "the two complaints are concluded that psoriatic arthritis is common in patients with severe intimately connected and due to a common cause". The current knowl¬ psoriasis and that it is associated with more extensive skin disease than edge of this condition has been sumis found in patients without arthritis. marized by Wright and Moll.6 They categorized psoriatic arthritis under the Resume: L'arthrite psoriasique dans les clinical headings: (a) distal following cas s6veres de psoriasis interphalangeal (DIP) joint arthritis, often associated with nail changes; (b) Sur 100 malades hospitalises pour traitement de psoriasis 32 presentaient psoriatic dactylitis, in which there is coincident synovitis in the interphalan¬ des signes cliniques ou radiologiques d'arthrite psoriasique et 17 d'entre geal joint and the flexor tendon sheath; eux avaient les deux types de signes. (c) large joint arthritis, often asymmeChez huit malades on notait des signes tric; (d) sacroiliitis and spondylitis; (e) arthritis mutilans (a severe form of radiologiques d'une atteinte, du erosive peripheral arthritis); and (f) co¬ reste asymptomatique, de la colonne incident psoriasis in rheumatoid ar¬ vertebra le ou de la region sacroiliaque.

thritis. Chez sept autres on notait des signes In this paper we report the results cliniques d'arthrite peripherique of a clinical, radiologic and laboratory sans signes radiologiques. II etait study of psoriatic arthritis among 100 plus que probable que les malades souffrant de sacroileite et de spondylite patients with psoriasis. d'origine psoriasique presentaient les alterations radiographiques les plus Patients and methods typiques. Nous croyons done pouvoir The study group comprised 100 pa¬ conclure que la polyarthrite psoriasique tients admitted to a general hospital est une decouverte courante parmi les malades souffrant de psoriasis severe et que,

dans

ces cas,

les lesions

plus etendues que chez les psoriasiques qui ne souffrent cutanees sont

dermatology division for treatment of psoriasis. Clinical evidence of psoriatic arthritis was sought. Psoriatic involve¬ ment was graded as being absent, mild, moderate or severe (giving a scale from 0 to 3) in scalp, trunk, extremities, flexural areas, palms and soles, and nails. Thus, a patient with severe involvement of all six areas could have a score of 18. The estimation of the severity of the skin involvement and the search for musculoskeletal abnormalities were per¬ formed independently by different examiners. Radiologic evidence of arthritis was also sought. Laboratory investigations included determination of erythrocyte sedimentation rate (ESR) and serum uric acid concentration, and latex test¬ ing for rheumatoid factor.

Results

History Patients with arthritis had had pso¬ riasis for a mean duration of 22 years, compared to 20.3 years for the nonarthritic group. A history of psoriasis in the family was given by 40.6% of the arthritic group and by 41.0% of the nonarthritic group. Clinical and radiographic findings A total of 32 patients had evidence of psoriatic arthritis; 17 had both clin¬ ical and radiologic evidence. Eight pa¬ tients had asymptomatic axial involve-

Table I.Distribution of clinical involvement

by psoriatic arthritis

pas d'arthrite.

From the departments of medicine and radiology, Sunnybrook Medical Centre and

University of Toronto Reprint requests to: Dr. Hugh Little, Department of medicine, Sunnybrook Medical Centre, 2075 Bayview Ave., Toronto, Ont. M4N 3M5 CMA JOURNAL/FEBRUARY 8, 1975/VOL. 112 317

Nine patients had both clinical and with arthritis was 10.7. This difference radiographic changes in DIP joints. is significant at P < 0.02. For the 17 Two had only radiographic changes and patients with both clinical and radio¬ four had only clinical changes. graphic evidence of psoriatic arthritis the score was 12.5; the difference be¬ tween this score and 9.1 is very signi¬ only one clinical syndrome and 2 had Extent and distribution The mean score for psoriatic involve¬ ficant at P < 0.0005. all four. Only three patients were signi¬ Comparison of the distribution of ficantly incapacitated in their activities ment in patients without arthritis was of daily living because of arthritis; one 9.1 and the mean score for patients psoriatic lesions in patients with and patient required total care. Fig. 1 illustrates the development of incapacitat¬ ing arthritis (arthritis mutilans) in one patient. Examples of arthritis of DIP joints are shown in Figs. 2 and 3, and dactylitis in Fig. 3. An example of large joint arthritis is illustrated in Fig. 4. Radiographic abnormalities were ob¬ served in 25 patients; the commonest lesions were erosions and sclerosis about the sacroiliac joint, discovered in 20 patients. These abnormalities were associated with spondylitis in 11 pa¬ tients. Eleven patients had DIP joint changes and 10 had radiographic evid¬ ence of peripheral arthritis. Dactylitis, a clinical finding, could occasionally be recognized radiologically if the soft tissues of the affected digit were well seen. In all 10 patients with clinical evid¬ ence of axial involvement, radiographic evidence of such involvement was also obtained. Conversely, of 17 patients with clinical findings of peripheral ar¬ thritis only 9 showed typical radio¬ graphic changes. One patient had ra¬ diographic changes without clinical findings. Eight patients had asympto¬ FIG. IA.Clinical and radiographic features of severe progressive psoriatic arthritis

clinically but de¬ monstrated radiologically. Clinical evidence of one or more syndromes of psoriatic arthritis was noted in 24 patients (Table I); 11 had ment not discovered

matic sacroiliitis.

(arthritis multilans), 1950

plaques

FIG. 1B.By 1954 generalized psoriasis had developed and hand was affected by dactylitis of all digits and edema.

over

to 1963. Hand in 1950 was normal except for psoriatic dorsum and nail changes. Radiographically normal hand in 1950.

FIG. 1C-.By 1963 hand had become grossly deformed. Radiographic abnormalities of hand in 1963 included disorganization and subluxation of wrist, loss of ulnar styloid process, subluxation of all metacarpophalangeal joints, and "pencil and cup" deformity of interphalangeal joint of thumb.

318 CMA JOURNAL/FEBRUARY 8, 1975/VOL. 112

without arthritis is given in Table II. Involvement of palms, soles and nails was more frequent in those with arthritis. Laboratory findings A positive test for rheumatoid factor was obtained in 10% of the total group; three patients had titres of 1:1280 or more, only one of whom had clinical evidence of arthritis. The mean serum uric acid value was 6.9 mg/dl in the arthritic group and 6.5 mg/dl in the nonarthritic group. (Both figures lie within the middle range of normal values as determined by our !aboratory.) FIG 2-Psoriatic nail changes in both thumbs showing onycholysis and pitting. Note swelling of interphalangeal joint (arrow)

FIG. 3-Psoriatic lesions of skin and nails. Note swelling of distal interphalangeal joint of second toe and proximal interphalangeal joint of third toe. Note also diffuse swelling of third toe, associated with tenderness of flexor tendon sheath, and dactylitis.

k

Discussion Although the estimated prevalence of arthritis in the psoriatic population is 5 to 7% ,. Baker and Ryan7 found a prevalence of 32% in a group of 104 patients with generalized pustular psoriasis. They noted that arthritis was particularly prevalent in patients with erythroderma or the flexural form of pustular psoriasis. No one appears to have attempted to correlate the prevalence of arthritis with the extent of psoriasis. In making visual estimates of the extent of disease involving various areas, we found the difference in mean scores between groups of patients with and without arthritis to be statistically significant. Thus, severe psoriasis is more likely to be complicated by arthropathy than mild disease, even though individual patients with very mild, often unrecognized psoriasis sometimes do present with classic psoriatic arthritis. The duration of skin disease was similar in the arthritic and nonarthritic patients and a family history of psoriasis was obtained from about 40% of patients in both groups. Previous authors have stressed that elevated serum uric acid values, due to increased cellular turnover in the skin, can be found in patients with extensive psoriasis.3 But these increases tended to be small, and in our patients with severe psoriasis the mean serum uric acid value was within normal limits. Clinical evaluation and radiographic evaluation each were sensitive aids to detection of different forms of psoriatic arthritis. We found that in the detection of sacroiliitis and spondylitis radiographic evaluation was relatively more

sensitive, whereas in the detection of peripheral arthritis clinical evaluation was more sensitive. The cause of psoriasis is still unknown. Genetic factors are apparently important, although the precise mode of inheritance has not been defined.8 Seronegative arthritis has been found in 6.6% of siblings of patients with psoriatic arthritis, which is four times the expected prevalence. Psoriatic arthritis is found in 5.5% of relatives of patients with psoriatic arthritis. This clustering of psoriatic arthritis in families suggests that this is a disease entity related to but separate from the associated psoriasis.5 Recently, studies of histocompatibility (HL-A) antigen types have shown a high prevalence of W27 in patients with ankylosing spondylitis.'0 And preliminary studies have shown a high prevalence of W27 in patients with sacroiliitis and spondylitis associated with psoriasis.1' Conclusion Psoriatic arthritis is common in patients with severe psoriasis and is associated with more extensive skin disease than is found in those patients without arthritis. Sacroiliitis and spondylitis produced the commonest radiographic changes; spinal disease is often asymptomatic. We are most grateful to Drs. C. W. Wyse, L. From and C. M. Leneck for allowing us to study their patients, and to Dr. F. Demanuele for the statistical analysis. References 1. INGRAM JT: The uniqueness of psoriasis. Lancet 1: 121, 1964 2. WRIGHT V: Rheumatism and psoriasis. Am J Med 27: 454, 1959 3. EisaN AZ, SEEGMILLER JR: Uric acid metabolism in psoriasis. J Clin Invest 40: 1486, 1961 4. SIGLER JW: Psoriatic arthritis (chap 42), in Arthritis and Allied Conditions, eighth ed, edited by HOLLANDER J, Philadelphia, Lea & Febiger, 1972 5. GARROD A, EVANS G: Arthropathia psoriatica. Q I Med 17: 171, 1924 6. WRIGHT V, MOLL JM: Psoriatic arthritis. Bull Rheum Dis 21: 627, 1971 7. BAKER H, RYAN T: Generalized pustular psoriasis. Br I Dermatol 80: 771, 1968 8. STEINBERG AG, BECKER SW, FITZPATRICK TB, et al: A genetic and statistical study of psoriasis. Am I Hum Genet 3: 267, 1951 9. MoLLJMH, WRIGHT V: Familial occurrence of psoriatic arthritis. Ann Rheum Dis 32: 181, 1973 10. ScmossTEmt L, TERASAKI P, BLUESTONE R, et al: High association of an HL-A antigen, W27, with ankylosing spondylitis. N Engl / Med 288: 704, 1973 II. RODMAN GP, RABIN B, MEDEGER TA, et al: HL-A antigen 27 and psoriatic spondylitis (abstract). / Rheumatol 1 (suppl): 12, 1974

Table Il-Distribution of psoriatic lesions in patients with and without arthritis

FIG. 4-Psoriatic plaques and synovial effusions of both knees.

Patient group With arthritis Without arthritis

Frequency (%) of lesions at different sites Palms, soles Flexures Nails 56 87 93 44 90 78 CMA JOURNAL/FEBRUARY 8, 1975/VOL. 112 319