BAD Report 2014: Leprosy – could be misdiagnosed

Report from the British Association of Dermatologists annual meeting held in Glasgow from 30th  June -3rd July 2014 by Christine Clark.  Dermatologists from Cardiff warned that cases of leprosy can be misdiagnosed as more common skin conditions. Two cases illustrate the point: the first, aged 25, had been experiencing changes to skin colour and sensation on the left side of his face for six months, and lightening of the skin on his right shoulder for a year. The symptoms on his face had been previously misdiagnosed as erysipelas, while the skin lightening was treated as pityriasis versicolor. The second man, aged 35, had scattered patches of skin lightening over his body, raised plaques on his forehead, and circular lesions on his legs. These lesions were associated with altered skin sensation. He was initially diagnosed with discoid eczema. Both men were subsequently diagnosed by dermatologists as having leprosy and referred to infectious disease specialists for appropriate treatment. Both patients had moved from Asia within the past few years.

Leprosy is a chronic infection caused by Mycobacterium leprae and Mycobacterium lepromatosis. Symptoms can occur years or even decades after initial infection. It causes lesions on the skin and diminished or loss of sensation in the affected areas, which can eventually cause further complications. The characteristic damage to hands, feet and face is not caused by the disease itself but of the loss of sensation in those areas. Minor trauma such as burns, scratches or something as simple as a stone in a shoe, can go unnoticed and result in serious injury and infection.  Leprosy is not highly contagious and it is not fully known how it is passed from person to person but it is thought to be via droplets from the nose and mouth. The spread of leprosy is caused by close and frequent contact between a person who is genetically susceptible to developing the disease and an untreated patient.

It is a relatively rare disease with approximately 232,000 cases reported annually worldwide, the majority of which occur in south-east Asia. 129 cases were reported in England and Wales between 2001 and 2010.

Dr Ausama Atwan, one of the reporting clinicians in Cardiff, said the leprosy is something that doctors should keep in mind especially if they encounter patients who come from countries where the disease is endemic with persistent or unexplained lesions and changes in skin pigmentation and sensation.