Hand Mycetoma: The Mycetoma Research Centre Experience and Literature Review
Authors: Rowa Fathelrahman Omer, Nancy Seif EL Din, Fadwa Awad Abdel Rahim, and Ahmed Hassan Fahal
Journal: PLOS Neglected Tropical Diseases
The Mycetoma Research Centre (MRC) at the University of Khartoum in Khartoum, Sudan is a World Health Organization collaborating center that researches mycetoma, a neglected tropical disease, and treats patients affected by it. Mycetoma is a subcutaneous infection caused by either bacteria or fungi that destroys tissue and often takes hold in extremities such as the hand. Between 1991 and 2015, the MRC managed 533 patients with hand mycetoma and has gathered a report on the data they collected.
In addition to conducting a review of their 553 hand mycetoma cases, the MRC stained surgical biopsies for histopathological examinations, analyzed x-rays, and used fine-needle aspiration. The MRC’s study is considered one of the largest ever and confirms that hand mycetoma is the second-most common location for mycetoma development.
The MRC’s statistical analyses reveal key data about mycetoma. First, they found that eumycetoma, the form of mycetoma caused by fungi, was much more prevalent than Actinomycosis (the form of mycetoma caused by bacteria), occurring in 83.3% of cases compared to 16.7 for Actinomycosis. Madurella mycetomatis is the most common agent of eumycetoma, and Streptomyces somaliensis and Nocardia spp. are the common causes of actinomycetoma.
The study found a large difference in patients affected by the disease based on their sex. 69.2% of patients were male, a sex ratio of 2.2 to 1. The authors note that some other studies have shown that sex hormones may play a role, but further research is required before this claim can be verified.
Figure 1: Table of Key MRC Data
Children and adolescents were affected most by mycetoma (28.1%), and only 15.8% of patients were above the age of 40. It is believed that the high rate of childhood disease is due to their more active lifestyles. Mycetoma can cause adolescents to drop out of school and may cause serious socioeconomic problems, which makes the uneven age distribution especially concerning.
This study also demonstrates mycetoma recurring nature. The MRC found that most of the patients had already had past surgery for mycetoma and that 32.6% of patients had had mycetoma for over five years. However, the authors of the MRC study point out that the longevity of hand mycetoma was found to be significantly less than mycetoma occurring in other parts of the body.
Most of the patients had lesions that were painless, which is accompanied by the fact that mycetoma can remain inactive for years. A history of trauma at the infection site was recalled by less than one fifth of patients, even though mycetoma is generally thought to occur due to skin-level trauma. 76.4% of the patients had no family history of mycetoma. These features of mycetoma make it extremely difficult to identify early and begin treatment.
Figure 2: Hand affected by Mycetoma
A problem with the MRC’s study is that they were unable to assess treatment outcomes due to patients dropping out before follow-up examinations. The MRC attributes this to high treatment costs, prolonged treatment time, and toxic side effects from prescribed drugs. Of the regularly followed up patients, 25% were cured.
The authors call for more research to better understand hand mycetoma, which has devastating impacts but is not thoroughly understood.