54 CLINICAL FOCUS
54 CLINICAL FOCUS
8 DECEMBER 2023 ausdoc . com . au
Case Report
Blue hue – what to do ?
A case of chronic upper limb discolouration and paraesthesia poses a quandary , when an essential medicine is suspected as the cause .
Dr Dan Xu Academic co-ordinator , general practice research and international health , Curtin Medical School , Curtin University , Perth , WA .
Soondus Ashraf Shoeib Senior medical student , Curtin Medical School , Curtin University , Perth , WA .
JEAN , an 86-year-old female , is a new admission to a nursing home . She reports she has had a few years of chronic bilateral upper limb discolouration . On the left upper limb this is associated with tingling pain on light touch . The symptoms have worsened in the last few months since an episode of rapid AF associated with heart failure , which required hospital admission for amiodarone loading .
Her past medical history includes AF with left ventricular dysfunction , gastrooesophageal reflux disease , osteoarthritis , constipation and diverticulitis . She has been taking amiodarone for rate control for 10 years and has been reasonably well controlled . She developed intolerable side effects with a trial of a beta-1 blocker .
Jean has no past history of eczema , chronic urticaria or contact dermatitis . There is also no history of chronic liver or kidney disease and no known exposures to heavy metals .
On examination , vital signs are within normal range , heart rate is 73 and irregularly irregular . Cardiorespiratory and abdominal
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examination are unremarkable , as is neurological examination , apart from the reported hyperalgesia on light touch in the left arm . Figure 1 depicts the bluish discolouration of the skin of the upper limbs .
Blood tests are within acceptable limits , she has stable mild renal impairment , and FBC , LFT and thyroid function tests are normal .
Diagnosis
The GP suspects amiodarone-induced skin toxicity .
Discussion
Amiodarone is a class III anti-arrhythmic drug which is indicated for the treatment of supraventricular and ventricular cardiac arrhythmias . 1 However , it has significant potential side effects , so is typically reserved for severe tachyarrhythmias , or those not responding to first-line therapies . Prolonged use may have multisystemic toxicity effects involving the thyroid gland , liver , lungs , eyes and skin . 1 , 6 , 7
Skin toxicity is the most common adverse effect . 1 This may manifest as phototoxic and photoallergic reactions , as well as hyperpigmentation . 1 Hyperpigmentation is relatively uncommon and reversible after drug withdrawal . 1
Symptoms of phototoxic and photoallergic reaction from amiodarone use include pruritus with sunlight exposure , with erythematous and eczematous appearance occurring at a minimal cumulative dose of 40g after four months of therapy . 1 Cases of blue to grey discolouration on the face , ears and hands have been reported in patients taking higher doses of amiodarone ( 400-800mg ) for over two years . 2 , 3 Additionally , cases have been reported in patients taking low doses over longer time frames .
Factors that increase the likelihood of developing skin discolouration include young age and total dosages of amiodarone , duration of treatment , the rate of amiodarone metabolism , frequency and intensity of exposure to sun . 2 , 3
Sensorimotor deficits have also been reported in association with amiodarone use . 4 The incidence of peripheral neuropathy associated with amiodarone has been found to be 2.38 per 1000 person-years . 4 The most significant risk factors are higher dose and duration of therapy , with neuropathy typically developing in those taking amiodarone for more than 18 months . 4
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