Mycetoma PDF

1. 2  Mycetoma is  A chronic  Localized  Subcutaneous  Slowly progressive  Relatively painless  Granuloma caused by both ◼ Actinomycetes (Actinomycetoma) or by ◼ True fungi (Eumycetoma).  It is characterized by  Destructive granulomato...

1. 2  Mycetoma is  A chronic  Localized  Subcutaneous  Slowly progressive  Relatively painless  Granuloma caused by both ◼ Actinomycetes (Actinomycetoma) or by ◼ True fungi (Eumycetoma).  It is characterized by  Destructive granulomatous and  Suppurative responses. 3  The disease was reported initially from India 300 years ago.  It was named Madura foot as the foot was the commonest site of infection.  The preferred name (Mycetoma) was introduced in 1861 to distinguish the disease from other tumors. 4 A. Eumycetoma More common in Sudan. Caused by: 1. Madurella mycetomatis ◼ Forms black Hard big grains and it is the most difficult mycetoma to treat. ◼ Constitutes about 70% of all mycetoma cases in Sudan. 2. Curvularia lunata ◼ Not common and forms black grains 3. Aspergillus nidulans ◼ Forms white soft big grains 5 B. Actinomycetoma Is a bacterial disease. Caused by: 1. Streptomyces somaliensis  Forms small hard yellow grains (Sandy grains) 2. Actinomadura madurae  Form big white soft grains similar to Aspergillus nidulans. 3. Actinomadura Pelletieri  Forms very small red grains. 4. Nocardia braziliensis  Forms white or creamy grains. 6 7  Common in tropics and subtropics.  Usually found in latitudes 15° – 30° N. (Mycetoma belt) where there is lots of savanna vegetations.  This type of climate favors acacia plants to grow. They have thorns in which the organisms live. 8  Depends on:  Temperature  Rain fall  Type of soil 9  Can affect both males and females, but males are more affected with a ratio of 5:1. (Genetic factor and outdoor activities).  Can affect any age group but common in 15 – 45 years. (Earning age).  Common in occupations in contact with soil like farmers, wood-cutters, diggers but as general no occupation is immune. 10 11  Starts in the subcutaneous tissue by direct penetration of a thorn contaminated with the organism.  Then organisms form colonies in the form of grains.  The host react to this by forming granuloma.  In earlier stages, presents as a small subcutaneous swelling may be soft or hard, increases in size gradually.  Later on, the skin get attached to the granuloma, sinuses open discharging pus with grains then progress to attack muscles and bones. But nerves and tendons are preserved. Therefore, it is painless. 12  Then bone destruction occurs and replaced by grains.  Mycetoma can affect any site. Commonly seen in the lower limbs, next in frequency in the upper limbs. Also can affect head, neck, chest, back, abdomen and perineum.  No internal organ is affected. Except in immunocompromised patients. Where we can find infection in the brain.  Usually the agent appears in infected tissues as compact grains or granules up to 5 mm in diameter. Their appearance may be diagnostic of the species involved. 13 14 15 16 17  Sometimes, primary mycetoma occurs in the superficial bones like the tibia and calcaneum by direct trauma of these areas by a sharp contaminated agent. Such lesions are discovered only by X-ray accidentally or during surgery.  Usually the distinctive radiological appearance is focal bone destruction with cavity formation. Cavities are generally small and abundant in cases of Actinomycetoma and less numerous and larger in eumycetoma. 18  Usually the spread of destruction occurs proximally as well as distally but the process involves only the lymphatics or the blood stream.  As general mycetoma results in local necrosis, multiple abscesses, osteitis and osteomylitis and formation of sinuses and fistulas that interconnect and erupt onto the skin surface. 19 20  The duration of the disease at presentation varies between 3 months to 30 years.  Patients tend to present late with advanced disease and this may be due to the nature of the disease which is painless and slowly spreading and also due to the lack of health education.  Clinical manifestations are almost identical irrespective to causative organism. Therefore, it is more rapid with Actinomycetoma than Eumycetoma. 21  Usually the clinical picture of the mycetoma may be influenced by one or a combination of the following factors:  Duration of the disease  Causative organism  Site of infection  Immune response of the host 22  To differentiate between Eumycetoma and Actinomycetoma:  Eumycetoma ◼ Localized with well defined margins ◼ Very slow progression ◼ Forms large few sinuses ◼ Bone involvement is very rare. ◼ Few big cavities.  Actinomycetoma ◼ More aggressive with ill defined margins ◼ Small many sinuses ◼ Some sinuses are actively discharging pus and grains. ◼ Bone involvement is earlier. ◼ Numerous small cavities 23  The swelling is usually firm and rounded but it may be soft, lobulated, rarely cystic and often mobile and it continues increasing in size.  Mycetoma of the head and neck is difficult to be treated and is the most dangerous because the granuloma which is formed may press on the brain causing neurological symptoms and signs and may lead to death. 24  Differential diagnosis of the mycetoma includes many of the soft tissue tumors as:  Kaposi’s sarcoma  Neurofibroma  Malignant melanoma  Fibrolipoma  Thorn granuloma  Tuberculosis,  Presence of bone destruction in absence of sinuses tend to favor the possibility of tuberculosis.  If sinuses present, it is found in the region of the joint line.  Osteogenic sarcoma  Comparable to the radiological features of advanced mycetoma. 25  The primary osseous mycetoma is to be differentiated from:  Chronic osteomylitis  Osteoclastoma  Bone cyst  Syphilitic osteitis 26 27 Good history taking Type of thorn Occupation Discovery of disease Originally coming from Hx of similar Residence condition Onset of disease Foot wearing during Site of infection transmission Color of grains Place of transmission Increase in size Ask about health Pain education about Sweating related to mycetoma lesion 28  Examination  Swelling is usually firm and rounded but it may be soft lobulated rarely cystic and mobile.  Check fixation of the skin to the underlying tissue  Number and activity of sinuses 29  X-ray: looking for cavities.  Cavities are generally small and abundant and less numerous and larger in eumycetoma. 30  Collection of grains  Macroscopic examination: size, shape, color  Direct microscopy: crush grains between slides. Broad segmented hyphe in Eumycetoma.  Culture  Eumycetoma  Culture media blood agar  Growth in 2 – 3 days  White aerial mycelia growing in the top of the media.  Actinomycetoma  LJ media is used (rich media containing eggs)  Takes about 7 days.  Size, shape and color is dependant on the causative species.  Blood for serology 31 32  The morbidity of mycetoma in Sudan did not change and perhaps more than 400 new cases are seen in hospitals every year.  Medical treatment is important cause surgical treatment alone lead to 80% recurrence rate. 33  Actinomycetoma  Standard treatment is a combination of Streptomycin (14mg/kg/day for the 1 st month, and on alternating days thereafter) and Cotrimoxazole (14mg/kg twice daily)  If there is no response a combination of Streptomycin with one of the following:  Dapsone (1.5 mg/kg morning and evening)  Rifambicin (4.3 mg/kg morning and evening)  Fansidar  Recently, amikacin is used alone or in combination with cotrimoxazole. This regimen is reserved for patients with no response to the 1 st line treatment. (15 mg/kg/day divided into 2 doses/day for a week). But the cotrimoxazole continues for 5 weeks. The regimen is contraindicated when there is hepatic, ear or renal diseases. This therapy is given in cycles. 34  Eumycetoma  The drug of choice is ketoconazole. The dose is 200mg/twice daily. No significant side effects. Liver function test must be done every month during treatment.  The other choice, procaine penicillin 600,000 – 800,000 U/day given IM. 35  Surgery for mycetoma ranges from local excision to mass reduction and occasionally amputation of the affected part.  Also, surgery has a diagnostic role as well both excisional or incisional biopsies can be performed for histological diagnosis and mycological identification.  The aim of surgical treatment is complete removal of the lesion. This is possible in patients with early disease in which the granuloma is localized.  In patients with massive lesions, mass reduction is indicated. In such cases, the involved soft tissue is excised and the bone is curettaged.  Usually in advanced cases not responding to medical treatment for prolonged period nothing short for amputation to succeed. 36  In Sudan, the amputation rate ranges between 25 – 50% of advanced cases.  The recurrence rate with surgical treatment alone is high ranging from 20 – 90%. Therefore, medical treatment before surgery is recommended. Because high level of drug in circulation minimizes the chance of the organisms local spread.  Actinomycetoma has an ill defined border, therefore a margin of healthy tissue should always be excised with the lesion.  Simple bone curettage and soft tissue excision is recommended for localized bony lesions.  A bloodless operative field by using a tourniquet is mandatory, this helps to identify the grains in the tissues, if present and to remove them.  It is advisable to use iodine in the wound at the end of surgery.  Post operative wound dressing with anti-septic solution should continue till healing is achieved. 37 , 38  Health education which must including encouraging farmers to wear gloves and boots.  Early diagnosis  Early treatment 39. 40  Medical Bacteriology  Medical Microbiology (Greenwood)  Tropical Medicine and emerging infectious diseases  Sudan Medical Journal (Mycetoma is Sudan)  Lecture notes in Mycetoma (Prof. Samia Juma)  www.mycetoma.org  www.doctorfungus.com/mycetoma.htm  Hisham Abdelgadir. 41