Still's Disease Flashcards
Still’s Disease in Adults
Adult Still’s disease
typically affects 16-35 year olds
Features
TRIAD Polyarthralgia, Salmon Pink Rash + Fever
arthralgia
elevated serum ferritin
rash: salmon-pink, maculopapular of trunk/soles/palm/face
pyrexia
lymphadenopathy
hepatomegaly/splenomegaly
rheumatoid factor (RF) and anti-nuclear antibody (ANA) negative
can also present with chest symptoms including pleurisy and pleural effusions.
Ix:
A raised ESR, CRP and particularly high serum FERRITIN.
Mx:
Treatment of ASD involves systemic immunosuppresion, initially with prednisolone followed by DMARDs.
Still’s Disease in Adults - Example Question
A 39-year-old lady is referred to the acute medical clinic. She presents with a 3 weeks history of worsening shortness of breath and left-sided pleuritic chest pain. She denies a cough, sputum or haemoptysis. Her exercise tolerance, previously unlimited is now down to approximately 100 yards. She denies any weight loss but admits that she has been feeling hot and having fevers fairly regularly over the last 6 months. In addition, she complains of aches and pains in her knees and wrists for which she has been taking ibuprofen with reasonable effect. She is normally fit and well and on no regular medication. She is a non-smoker and drinks alcohol socially. She works as a secretary.
On examination she has a BMI of 21 kg/m², her temperature is 37.4ºC and her blood pressure is 128/67 mmHg with a heart rate of 76/min. Her respiratory rate is 19/min and her oxygen saturations are 96% on air. She has some submandibular and sublingual lymphadenopathy. She has reduced air entry at her left base with a stony dull percussion note. Examination of her cardiovascular and abdominal systems are unremarkable, as is an examination of her wrists and knees. You notice she has a salmon pink rash across her chest and upon questioning she admits that it has been there for the last few weeks.
Her blood tests show:
Hb 109 g/l Platelets 523 * 109/l WBC 19.3 * 109/l Neuts 14.5 * 109/l ESR 30 mm/hr Ferritin 2000 µg/l
Na+ 136 mmol/l K+ 3.6 mmol/l Urea 3.1 mmol/l Creatinine 70 µmol/l CRP 45 mg/l
Bilirubin 18 µmol/l
ALP 119 u/l
ALT 67 u/l
Albumin 34 g/l
Rheumatoid factor negative
ANA negative
Anti-histone antibodies negative
She has a chest x-ray which shows a medium-sized left pleural effusion.
What is the likely cause of her symptoms?
Non-Hodgkin's lymphoma Small cell lung cancer > Adult onset Stills disease Rheumatoid arthritis Mixed connective tissue disease
This lady has Adult Onset Stills disease. This is characterised by the presence of fever, salmon pink rash and arthralgia. It can also present with chest symptoms including pleurisy and pleural effusions. Other features include negative RF and ANA tests, anaemia, thrombocytosis and neutrophilia with deranged LFTs and a raised ESR, CRP and particular serum ferritin. Lymphoma and lung cancer are possibilities in this case but the presence of the rash and the high ferritin should point you towards AOST, although a lymph node biopsy would be prudent for this lady. Negative RF makes RA less likely in this lady as does the atypical presentation, similarly for Mixed connective tissue disease anti-histone antibodies are negative.
Still’s Disease in Adults - Diagnosis
Adult onset Stills disease (ASD) is a systemic inflammatory condition of unknown aetiology, but often thought to be secondary to a infectious trigger on a background of genetic predisposition. It classically presents in young adults under 40 years old, peaking between 15-25 years, with a daily fever and a new non-pruritic rash. The most sensitive diagnostic classification is the Yamaguchi criteria1. defined by a patient presenting with all major criteria and at least two minor criteria.
Major criteria:
Fever greater than 39 degrees over one week
Arthralgia or arthritis lasting two weeks or longer
Non-pruritic or maculopapular rash, salmon coloured, found on trunk or extremities, particularly during febrile episodes
Leucocytosis >10,000/microL
Minor critieria:
Sore throat, lymphadenopathy, hepatomegaly or splenomegaly, abnormal liver function tests, negative ANA or rheumatoid factor
Still’s Disease in Adults - Diagnosis: Example Question
A 27 year old male presents after recently returning from Bangladesh with 2 weeks of daily spiking fever, a new rash on his foot and pain on bending his knees or closing his hands. He also reports lumps and bumps on his neck that he thinks is new. He denies any cough or weight loss. He has no other past medical history and is unaware of any unwell family members. On examination, his temperature is 39.2 degrees. You note a maculopapular rash on his left sole and face. His knees and wrists are swollen and tender. His chest and cardiovascular examination are unremarkable, his abdomen is soft. However, you note a 12cm splenomegaly. His serum tests demonstrate:
Hb 12.7 g/dl
Platelets 450 * 109/l
WBC 17.0 * 109/l
Neuts 11.0 * 109/l
Na+ 138 mmol/l
K+ 3.5 mmol/l
Urea 7.8 mmol/l
Creatinine 70 µmol/l
CRP 30 mg/l Ferritin 2000 µg/l ALP 250 u/l ALT 160 u/l ANA negative dsDNA negative
His chest radiograph appears unremarkable with no focal consolidation. A first induced sputum is negative for acid fast bacilli. What is the diagnosis?
Miliary tuberculosis > Adult onset Stills disease Reactive arthritis post-travellers diarrhoea Porphyria cutanea tarda Systemic lupus erythematosus
A number of features in the history and examination should point you towards ASD. The nature of the fever is quoditian: ASD fevers tend to spike daily or twice daily. Secondly, the location of the rash is also characteristic, most commonly a salmon coloured rash in the trunk or the soles, palms and face. Knees, wrist and ankles are the most common sites for arthritis and arthralgias. Ferritin rises are characteristic of ASD, observed in up to 70% of patients2. Mild elevations in ALT and ALP are also characteristic of ASD. However, the patient does not describe a sore throat, which is often severe and non-suppurative in up to 70% of ASD patients. Treatment of ASD involves systemic immunosuppresion, initially with prednisolone followed by DMARDs.
The main differential to consider is TB. A two week history is short for miliary TB and particularly unusual for someone without chest signs. It typically is the result of a pulmonary focus eroding the pulmonary vein, leading to systemic dissemination. A negative induced sputum also points against miliary Tb but does not fully exclude it. SLE could also fit with the clinical picture but again, less likely with negative dsDNA and ANA. There is no suggestion that the patient has recently had GI symptoms. Reactive arthritis, formerly known as Rieters syndrome, does not account for the splenomegaly or serum abnormalities
Still’s Disease - Diagnosis: Example Question
A 45 year old patient comes in with a polyarthralgia. She is getting cyclical fevers along with the pain and also mentions she gets a salmon pink rash on her torso. She says she has had flares of this in the past and previously has been admitted to ITU for intravenous medications but she cannot recall their names. Her flares started in her late twenties. She has not had a flare for many years now. Her regular medications consist of paracetamol 1g PRN and naproxen 500mg PRN. On examination she is tender in most of her joints including her hips, knees, wrists, shoulders and the small joints of her hands. Her observations show heart rate of 110/min, respiratory rate of 24/min, blood pressure of 96/65mmHg, oxygen saturations of 98% on room air and temperature 39ºC. Her blood tests reveal:
Hb 135 g/l Na+ 136 mmol/l Platelets 269 * 109/l K+ 4.6 mmol/l WBC 8 * 109/l Urea 5 mmol/l Neuts 6 * 109/l Creatinine 90 µmol/l Lymphs 2 * 109/l CRP 55 mg/l Eosin 0.1 * 109/l Ferri tin 1559 ng/ml
What is her diagnosis?
> Adult-onset Still's disease Rheumatoid arthritis Septic arthritis Psoriatic arthritis Tuberculosis
This patient is suffering from adult-onset Still’s disease shown by the triad of fever, polyarthralgia and rash. The raised ferritin is another hint at the diagnosis as ferritin is the acute phase protein of choice for monitoring disease activity in these patients. Adult-onset Still’s disease can lead to severe flares that mimic sepsis.
A range of biologic therapies can be used to treat these flares such as anti-TNFs and anakinra along with more traditional disease modifying anti rheumatic drugs (DMARDs) and non-steroidal anti inflammatories.
Rheumatoid arthritis would be a differential but the triad listed is more associated with Still’s disease. In this case it is adult onset Still’s as it started in her twenties. Septic arthritis tends to be monoarthritis or occasionally an oligoarthritis not a polyarthritis hence this is not the correct answer. The rash described is not that psoriasis.
