A 32- year-old married woman experiences difficulty in walking and swelling in knees, ankles, wrists, and left elbow

Case discussion June 2013

Mrs RK, a 32- year-old married woman suffering from joint pain for the past 6 years, attended our OPD clinic. For the past 3 months, the patient was experiencing difficulty in walking and restricted movement of both shoulders and elbows. She had swelling in knees, ankles, wrists, and left elbow. For the past 2 months, an increase in the severity of joint pain and the occurrence of a dry cough, especially towards night, was observed. The patient was on regular MTX and SSZ as per the previous dug prescriptions..

No fever or breathlessness was reported. She complained of minimal dry mouth. Few rashes on the trunk were noticed by the patient, which were pruritic and transient.

She was diagnosed to have rheumatoid arthritis by her primary care physician and was regularly on MTX 5mg per week, and salazopyrine 500mg two times daily. Whenever pain was severe, different NSAIDs and prednisolone were taken.

The patient was moderately built and adequately nourished. Her general examination was not remarkable and had no skin rashes at the time of examination. She had deformed hands and foot. Knee, ankle, elbow, and wrist were swollen and tender. The examination of chest revealed good air entry throughout all lung fields and minimal crepitation at lung base. CVS and per Abdomen examination was not remarkable. CNS and peripheral nervous system were normal. Results of diverse parameter estimation are given in table 1.

Discussion:

The current patient is a female with symmetrical deforming arthritis from past 6years, treated with methotrexate and salazopyrine. Her investigation revealed positive RF and the skin lesions described are not suggestive of Psoriasis. She has minimum dry mouth, no dry eyes. The patient was treated with inadequate doses of MTX and SSZ. Though asymptomatic on examination of chest revealed rales and crepitation in scapular area; suggest a possible interstial Lung disease. The patient is suffering from rheumatoid arthritis. In this case diagnosis of rheumatoid arthritis is obvious. But we need to draw our important attention on pulmonary findings, low WBC counts and severe disability because of deformity as well the disease activity.

The probability surrounding this situation is –RA is not adequately controlled though treated with the DMARD. The patient has moderate leukopenia and probable Interstial lung disease. In this patient we need to look for the cause of leucopoenia and the cause for respiratory findings. With reference to both patients are asymptomatic.

The causes for leukopenia could be drug- induced- methotrexate or sulfasalazine or combination. However the dose prescribed is sub optimal and in that dosage it rarely causes leucopoenia at such lower dose.  One need to consider a possible overlap connective tissue disease or a possible felty's syndrome. Clinical examination does not reveal splenomegaly and investigation reveal ANA is negative. The Respiratory findings suggest a possible ILD, though patient donot have cough or breathlessness. In the current patient breathlessness is not obvious since mobility is significantly restricted. The patient should undergo HRCT chest, Diffusion Lung Capacity for CO along with Pulmonary Function Test (PFT). The evaluation for ILD is required since its presence influence  the treatment decision.

The presence of ILD changes raises two possibilities; first possibility is lung involvement to RA and an alternative possibility is due to methotrexate. Clinical relationship, CT finding and status following transient withdrawal of MTX can help us to conclude the diagnosis.

The treatment from primary physician is not adequate. Though combination used are suitable DMARD the target of treatment was not adequate as per current recommendation. Current recommendations of treat to target are to achieve tighter control of RA and to maintain reduced disease activity at minimum as long as possible.  This need to be achieved this has been attributed to reduce the deformity and long term disability in patients with RA. For details how to differentiate between primary ILD and MTX lung disease read in next section.

Management plan in this patient should include optimizing DMARD therapy, rehabilitation of the patient from the existing deformities. The keeping in view of leukopenia one may have to investigate the cause for leukopenia. Majority of the discussant has missed their focus on this issue. Assessing serum B 12 level and folic acid will assist to ascertain their deficiency being responsible for it. In this patient the levels of B 12 and folic acid were low explaining the reduced WBC count and Platelet. Norma Haemoglobin suggest a recent acute deficiency probably nutritional compounded by low dose Mtx.

Discussion on investigating and differentiation of ILD vs MTX lung involvement see Q and A on methotrexate.

References:

1. Rojas-Serrano J, González-Velásquez E, Mejía M, Sánchez-Rodríguez A, Carrillo G Interstitial lung disease related to rheumatoid arthritis: evolution after treatment. Reumatol Clin. 2012 Mar-Apr;8(2):68-71. doi: 10.1016/j.reuma.2011.12.008. Epub 2012 Feb 15)
2. Gochuico BR, Avila NA, Chow CK, Novero LJ, Wu HP, Ren P, MacDonald SD, Travis WD, Stylianou MP, Rosas IO Progressive preclinical interstitial lung disease in rheumatoid arthritis. Arch Intern Med. 2008 Jan 28;168(2):159-66. doi: 10.1001/archinternmed.2007.59