Atlas of Psoriatic Arthritis
P. J. Mease and P. S. Helliwell Although initially thought to be a variant of rheu- Despite clinical, radiological and familial e- matoid arthritis (RA), the pioneering work of dence supporting PsA as a distinct disease entity, Wright and Baker identi? ed the distinctive fea- controversy still exists about which patient to tures of the arthritis occurring in association with include within this disease group. Some authors psoriasis . Wright described the frequent have even questioned whether PsA is a separate involvement of the distal Interphalangeal (DIP) disease, suggesting that psoriasis merely modi? es joints with erosion and absorption of the terminal the expression of pre-existing RA. Other authors phalanges and frequent reduction of bone stock have argued that new onset chronic polyarthritis in the other digits leading to a mutilating form is undifferentiated and only evolves into a more of arthritis. Wright also described sacroiliitis and distinctive form with time such that the presence spondylitis occurring alone and in association of psoriasis at onset of disease is of no value in with peripheral arthritis. The original ? ve clinical nosological terms . The problem is not with the sub-groups described by Moll and Wright are still classical presentation of PsA – with oligoarthritis, in use today although the validity of this classi? ca- DIP involvement, calcaneal enthesitis, and dac- tion has been challenged  (see Figure 3. 1).
Visual reference and data source of the most up-to-date findings and comprehensive images of PsAServes as a first point of reference both for diagnosis and treatment decisions