Adult Onset Still's Disease With Pulmonary Nodules - A Case Report

Abstract

INTRODUCTION: Adult onset still's disease is an inflammatory disorder characterised by high spiking fever,skin rash,lymphadenopathy,hepatosplenomegaly,arthritis,myalgia associated with lab characteristics such as neutrophilic leucocytosis,high ESR,RF and ANA being negative and high Serum Ferritin levels and respond to immunosuppressive therapy mainly corticosteroids1.We present a case of Adult onset still's disease complicated with pulmonary manifestations which responded to immunosuppressive therapy with corticosteroids. CASE PRESENTATION: A 19 Year old Caucasian female presented with high spiking fever,cough,myalgia,arthralgia,skin rash,sore throat for 20 days.On examination,patient was non-toxic,febrile with Pallor,hepatomegaly and auscultatory finding of bilateral fine inspiratory crackles in lung bases.Prior to admission,she had been started on Anti tubercular therapy based on CT scan features without any improvement even after 2 weeks.She was started on empirical antibiotics and antimalarial with no relief. Lab findings revealed a total leucocyte count of 30400 with neutrophilic predominance,normal platelet count,Hb-10g%,renal and liver function tests-normal,FBS/PPBS-normal,Thyroid function test-normal,Malarial parasite-negative,Dengue IgM,IgG,NS1 Ag-non reactive,Sickling test-negative,Hb electrophoresis-normal,Sputum for AFB-negative,Urine routine,microscopy-normal,HIV,HBsAg-negative,Widal-negative,CRP-88mg/L,Rheumatoid factor-negative,ANA-negative,Angiotensin converting enzyme-28U/L,USG abdomen showing hepatomagaly,Blood culture-negative,Serum ferritin -27000 ng/mL with chest Xray showing nodular shadows bilaterally in lower zones. HRCT thorax revealed multiple centrilobular nodules in bilateral lower lobes.Bronchoscopy was normal and bronchial washings for AFB and other microorganisms were negative.2D Echocardiography was normal. As patient's symptoms persisted with empirical antibiotics and antimalarial,based on above clinical findings and lab reports which satisfied the Yamaguchi criteria,diagnosis of Adult onset still's disease was established.Antitubercular therapy,Antibiotics,Antimalarial were stopped and the patient was started on parenteral corticosteroids(Inj.Methyl prednisone 1 g/day for 5 days) and patient had immediate relief.Parenteral corticosteroid was tapered and discharged with Oral corticosteroid(Tab.Prednisone 40mg daily).On the 30th day of follow up, patient was asymptomatic,TLC-6100,S.Ferritin-814.35,CRP-12,HRCT thorax showing improvement with only a few ill defined nodules.Patient was followed up every 3 months for one year without any relapse. DISCUSSION: The incidence of AOSD is around 1.6 per million population with equal representation of genders and a bimodal age distribution of 15-25years and 36-45years.Etiology is unknown although genetic predisposition combined with viral triggers have been proposed. Pulmonary involvement in AOSD is seen in 50-60% of cases, with most common pulmonary manifestations being pleural effusion(26.4%) and transient pulmonary infiltrates.Life threatening complications such as ARDS, diffuse alveolar haemorrhage have also been reported.This patient was diagnosed as AOSD according to the Yamaguchi's (93.5%sensitive) classification criteria as the patient fulfilled all the major criteria and 4 out of 5 of the minor criteria2.And also fulfilled the classification criteria by Fautrel(98.5% specificity), where 5 out of 6 major criteria and all the minor criteria were fulfilled3. Alternative diagnoses such as infection, malignancy and other rheumatic diseases had been ruled out. Fever,hyperferritinemia, hepatosplenomegaly, haematological abnormalities are mainly due to IL-6 and TNF-α.IL-18 is the most important cytokine involved in AOSD and is believed to initiate the inflammatory cascade.The corner stone in treatment of AOSD is Corticosteroids along with NSAIDS and DMARDs. CONCLUSIONS: Even though AOSD is a rare condition,it has to be considered in the differential diagnosis of FUO (Fever of unknown origin) with an initial negative workup for infection and malignancy. An early diagnosis can be life saving as it can lead to fatal complications like MAS (Macrophage activation syndrome) and DIC (Disseminated intravascular coagulation).