Coding and Understanding Hansen’s Disease (Leprosy)

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By Maria Ward, MEd, RHIT, CCS-P

A few weeks ago, an article came to me from a co-worker about World Leprosy Day, which is the last Sunday of January each year. I was under the naïve impression that leprosy had been, for the most part, eradicated. I had no idea the extent to which leprosy still existed, much less that there was a whole day dedicated to it. According to the World Health Organization, more than 200,000 cases were reported worldwide in 2015. Have I been living under a rock? With this revelation, I thought it might be interesting to share some information about leprosy with our Journal of AHIMA blog readers.


Leprosy, now known as Hansen’s disease, is an infection caused by the bacteria Mycobacterium leprae, which was discovered by Norwegian doctor Armauer Hansen in 1873. This slow-growing bacteria attacks peripheral nerves, skin, and mucous membranes, and can take anywhere from two to 20 years before the infected person shows any signs or symptoms. Some of the first signs are spots of hyper- or hypopigmentation that may eventually become numb. Hair loss in these areas is also possible. If left untreated, the numbness and loss of sensation in the extremities can eventually progress to muscle paralysis. Contractures, wounds, and infection can also develop. If the bacteria invades the facial nerves it could affect the eyes, potentially leading to blindness. Nasal deformities can also occur if the infection spreads into the mucous membranes.

To demonstrate how slowly the disease can spread, the story of Father Damien is a perfect example. When I heard there was still a leper colony on the island of Moloka’i in Kalawao, Hawaii, I asked my husband about it since he had grown up in Hawaii. Joseph De Veuster was born in Belgium in 1840. He traveled to Honolulu in 1864 and was ordained on May 31. He took the name Damien, and in 1873 made the decision to serve those who had been exiled to Moloka’i and the leper colony. It was 12 years later before he was diagnosed, and he continued to serve in the colony until the he passed away on April 15, 1889. You can read more about Father Damien and his efforts to help the victims of leprosy at

Diagnosis and Treatment

So how does this potentially lethal disease spread? Unless you have a very close relationship with an infected armadillo, scientists believe Hansen’s disease is spread through the inhalation of bacteria-carrying droplets from the cough or sneeze of an infected person over a long period of time. As the discolored patches appear on the skin, diagnosis can be made with a skin or nerve biopsy. Treatment today consists of a one- to two-year multidrug therapy regimen of dapsone, rifampicin, and clofazimin. However, any damage that an infected patient has experienced is irreversible.

Coding of Leprosy

Leprosy can be indexed under the main term Leprosy. Even if you look up Hansen’s disease, the index will tell you to see Leprosy. Leprosy falls into the category of A30.- which is in the section Other bacterial diseases. As you can see from the index entry below, if the patient has a muscle disorder associated with the leprosy, an additional code for an M63.8- Disorders of muscle in diseases classified elsewhere, is also coded as a secondary code.


Centers for Disease Control and Prevention page on leprosy:

World Health Organization fact sheet on leprosy:


Maria Ward ( is director of HIM practice excellence, coding services.

1 Comment

  1. prof premraj pushpakaran writes — let us celebrate World Leprosy Day!!!

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