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PubMed This is a summary of 24 peer-reviewed journal articles Updated

Recognizing Symptoms and Warning Signs

At a Glance

Mycetoma often begins as a painless, slowly growing lump and may later cause draining skin openings with visible grains. New pain, rapid swelling, redness, fever, numbness, or loss of movement may signal complications and need prompt medical assessment.

Because mycetoma grows very slowly—often over months or even years—it can be easy to overlook the early signs [1][2]. However, understanding the typical progression of this infection and knowing which symptoms are “red flags” is critical for getting the right treatment before permanent damage occurs [3][4].

The Classic Triad of Symptoms

Doctors often look for a “classic triad” of three signs that strongly suggest mycetoma [5][3]:

  1. Painless Swelling: A firm, slow-growing lump under the skin (a subcutaneous mass) [5].
  2. Draining Sinuses: Small openings or tunnels (sinus tracts) that form in the skin over the lump and leak fluid [5].
  3. Visible Grains: Tiny, seed-like particles, called grains, that are discharged through the sinus tracts [3].

It is important to know that you may not have all three symptoms at once. In the early stages, you might only have a single, painless lump without any draining holes or visible grains [6][7]. Because these early lumps are usually not painful, many people wait years before seeing a doctor—in some cases, the infection has been present for over a decade before a diagnosis is made [1].

Grains: A Clue to the Cause

The grains found in the drainage are actually clusters of the bacteria or fungi causing the infection [3]. Their color can provide your medical team with an early clue about which type of mycetoma you have, though lab tests are always needed for confirmation [8][9].

Grain Color Most Common Association What it Suggests
Black Eumycetoma (Fungal) Highly likely to be a fungal infection [10].
Red Actinomycetoma (Bacterial) Often points to a specific bacterium (Actinomadura pelletieri) [11].
White or Yellow Either Type Can be caused by certain bacteria OR certain fungi [12][13].

While these colors are helpful, they are not a perfect rule. For example, some rare bacteria can produce black grains, and some fungi can produce pale ones [8][12]. This is why your doctor must perform a biopsy or use molecular tests to be certain [14].

Normal Progression vs. Urgent Red Flags

Typical mycetoma is a chronic infection that moves slowly and often doesn’t cause pain [5]. However, certain changes mean the infection is becoming more aggressive or that a new complication has developed.

Seek medical attention for the following situations:

  • Routine Follow-up: A persistent painless lump should be evaluated, but it is typically not an emergency.
  • Urgent Same-Day Assessment for Pain, Swelling or Redness: While the lump itself is often painless, new or intense pain, or if the area suddenly becomes hot, very red, or swells much faster than usual, this often indicates an acute secondary bacterial infection (a “superinfection”) on top of the chronic mycetoma [15][16][17].
  • Urgent Same-Day Assessment for Fever and Chills: Mycetoma usually stays in one area of the body. If you develop a fever or feel generally unwell, it could mean a severe secondary infection is occurring. In rare cases, if you experience confusion, fainting, or difficulty breathing, the infection may have reached your bloodstream (sepsis), which is a life-threatening emergency [18][19].
  • Loss of Movement or Numbness: If you can no longer move the nearby joint or if you feel “pins and needles” or numbness, the infection may be pressing on nerves or invading deep muscles and tendons [20][21].

The Hidden Spread

Because clinical exams only see the surface, they often underestimate how deep the infection has gone [22]. Even if you only have a small lump, the infection may have already spread along tissue planes (the layers between muscles) or begun to affect your bones, although advanced bone destruction is not necessarily present in every early lesion [22][23]. Imaging tests like MRI or CT scans can be used to see the full extent of the disease before treatment begins [23][24].

Common questions in this guide

What are the main symptoms of mycetoma?
The classic triad is a painless, slowly growing lump, draining openings in the skin, and grains in the drainage. Early mycetoma may cause only a lump, so the absence of drainage or grains does not rule it out.
What do black, red, white, or yellow grains mean?
Black grains are strongly associated with fungal eumycetoma, while red grains often point to bacterial actinomycetoma, including infection caused by Actinomadura pelletieri. White or yellow grains can occur with either bacteria or fungi, so laboratory testing is needed to confirm the cause.
When should I seek urgent care for mycetoma symptoms?
New severe pain, rapidly worsening swelling, heat or redness, fever, chills, or feeling very unwell requires same-day medical assessment because it may signal a secondary bacterial infection. Confusion, fainting, or difficulty breathing are emergency symptoms that may indicate sepsis.
Can mycetoma spread beneath the skin?
Yes. Mycetoma can extend along tissue planes and involve muscles, tendons, or bones even when the surface lump is small. Imaging such as an MRI or CT scan may help show the full extent of the infection before treatment.
How is bacterial or fungal mycetoma diagnosed?
A doctor may use a biopsy, culture, or PCR or other molecular testing to identify the cause. Grain color can provide a useful clue but cannot reliably confirm which organism is responsible.

Questions For You

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Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What specific tests—such as a biopsy, culture, or PCR—will you use to confirm whether my infection is bacterial or fungal?
  2. 2.Based on the color of the grains I've seen, which causative organism do you suspect most, and how does that change my treatment plan?
  3. 3.If I experience sudden new pain or a fever, what is the best way to contact your team for an urgent evaluation?
  4. 4.Do you recommend imaging, like an MRI or ultrasound, to check if the infection has spread to my muscles or bones before it becomes visible on the surface?
  5. 5.How can we tell if my symptoms are from the mycetoma itself or from a secondary bacterial infection that needs separate treatment?

References

References (24)
  1. 1

    Clinical triad with multi-biopsy histopathology as a reliable diagnostic marker of mycetomas: a retrospective review from a tertiary care center.

    Ansari F, Singh S, Bhardwaj A, et al.

    International journal of dermatology 2023; (62(1)):88-96 doi:10.1111/ijd.16384.

    PMID: 36030528
  2. 2

    Predictors of Post-operative Mycetoma Recurrence Using Machine-Learning Algorithms: The Mycetoma Research Center Experience.

    Wadal A, Elhassan TA, Zein HA, et al.

    PLoS neglected tropical diseases 2016; (10(10)):e0005007 doi:10.1371/journal.pntd.0005007.

    PMID: 27798643
  3. 3

    Mycetoma: The Spectrum of Clinical Presentation.

    Fahal AH, Suliman SH, Hay R

    Tropical medicine and infectious disease 2018; (3(3)) doi:10.3390/tropicalmed3030097.

    PMID: 30274493
  4. 4

    A holistic approach to the mycetoma management.

    Bakhiet SM, Fahal AH, Musa AM, et al.

    PLoS neglected tropical diseases 2018; (12(5)):e0006391 doi:10.1371/journal.pntd.0006391.

    PMID: 29746460
  5. 5

    Dot-in-Circle Sign - A Diagnostic MRI Sign for "Madura Foot".

    Javed F, Nazir R, Sharma M, et al.

    Journal of the College of Physicians and Surgeons--Pakistan : JCPSP 2017; (27(3)):S8-S10 doi:236.

    PMID: 28302229
  6. 6

    A rare presentation of actinomycotic mycetoma of the hand: a case report.

    Layegh Mirhosseyni S, Abdi A, Kord M, et al.

    BMC infectious diseases 2026; (26(1)).

    PMID: 41680662
  7. 7

    Mycetoma patients in Ethiopia: case series from Boru Meda Hospital.

    Tilahun Zewdu F, Getahun Abdela S, Takarinda KC, et al.

    Journal of infection in developing countries 2022; (16(8.1)):41S-44S doi:10.3855/jidc.16047.

    PMID: 36156501
  8. 8

    Cervicofacial Actinomycetoma Presenting with Black Grain: A Rare Clinical Scenario.

    Lodha S, Biswas S, Basu A, et al.

    The Journal of the Association of Physicians of India 2024; (72(8)):83-85 doi:10.59556/japi.72.0531.

    PMID: 39163074
  9. 9

    Mycetoma laboratory diagnosis: Review article.

    Ahmed AA, van de Sande W, Fahal AH

    PLoS neglected tropical diseases 2017; (11(8)):e0005638 doi:10.1371/journal.pntd.0005638.

    PMID: 28837657
  10. 10

    The genus Madurella: Molecular identification and epidemiology in Sudan.

    Ahmed EA, Nour BYM, Abakar AD, et al.

    PLoS neglected tropical diseases 2020; (14(7)):e0008420 doi:10.1371/journal.pntd.0008420.

    PMID: 32730340
  11. 11

    Direct 16S/ITS rRNA Gene PCR Followed by Sanger Sequencing for Detection of Mycetoma Causative Agents in Dakar, Senegal: A Pilot Study Among Patients with Mycetoma Attending Aristide Le Dantec University Hospital.

    Diongue K, Dione JN, Diop A, et al.

    Mycopathologia 2024; (189(5)):80 doi:10.1007/s11046-024-00891-w.

    PMID: 39249620
  12. 12

    Mycetoma caused by Microascus gracilis: a novel agent of human eumycetoma in Sudan.

    Mhmoud NA, Siddig EE, Nyuykonge B, et al.

    Transactions of the Royal Society of Tropical Medicine and Hygiene 2021; (115(4)):426-430 doi:10.1093/trstmh/trab010.

    PMID: 33515449
  13. 13

    The First Case of Fusarium falciforme Eumycetoma in Sudan and an Extensive Literature Review about Treatment Worldwide.

    Siddig EE, Ahmed A, Eltigani HF, et al.

    Journal of fungi (Basel, Switzerland) 2023; (9(7)) doi:10.3390/jof9070730.

    PMID: 37504719
  14. 14

    Comparing the performance of the common used eumycetoma diagnostic tests.

    Siddig EE, Nyuykonge B, Mhmoud NA, et al.

    Mycoses 2023; (66(5)):420-429 doi:10.1111/myc.13561.

    PMID: 36583225
  15. 15

    Painful mycetoma: a study to understand the risk factors in patients visiting the Mycetoma Research Centre (MRC) in Khartoum, Sudan.

    El-Amin SO, El-Amin RO, El-Sadig SM, et al.

    Transactions of the Royal Society of Tropical Medicine and Hygiene 2025; (119(2)):145-151 doi:10.1093/trstmh/trae093.

    PMID: 39611590
  16. 16

    Surgical management of eumycetoma: experience from Gezira Mycetoma Center, Sudan.

    Gismalla MDA, Ahmed GMA, MohamedAli MM, et al.

    Tropical medicine and health 2019; (47()):6 doi:10.1186/s41182-018-0129-2.

    PMID: 30675125
  17. 17

    [Multiple sites extrapodal actinomycetoma: Favorable outcome to treatment with a combination of cotrimoxazole and NSAI].

    Diallo B, Barro-Traoré F, Bamba S, et al.

    Journal de mycologie medicale 2015; (25(4)):297-302.

    PMID: 26547231
  18. 18

    The Surgical Treatment of Mycetoma.

    Suleiman SH, Wadaella el S, Fahal AH

    PLoS neglected tropical diseases 2016; (10(6)):e0004690 doi:10.1371/journal.pntd.0004690.

    PMID: 27336736
  19. 19

    Unusual extra-podal fungal mycetoma with black grains in a Senegalese child.

    Seck B, Diop A, Ndiaye MT, et al.

    Journal de mycologie medicale 2020; (30(1)):100914 doi:10.1016/j.mycmed.2019.100914.

    PMID: 31864802
  20. 20

    Advanced Eumycetoma of the Right Foot Resulting in Below-Knee Amputation in Somalia: A Case Report.

    Mahamud MA, Ahmed MM, Hassan SA, et al.

    International medical case reports journal 2026; (19()):633948 doi:10.2147/IMCRJ.S633948.

    PMID: 42808000
  21. 21

    [Myelopathy secondary to thoracic actinomycetoma].

    Damián-Zapién A, Covarrubias-Gutiérrez D, Rodríguez-Virgen JE, et al.

    Revista medica del Instituto Mexicano del Seguro Social 2026; (64(1)):e6703 doi:10.5281/zenodo.17477391.

    PMID: 41417930
  22. 22

    Mycetoma imaging: the best practice.

    Bahar ME, Bakheet OELH, Fahal AH

    Transactions of the Royal Society of Tropical Medicine and Hygiene 2021; (115(4)):387-396 doi:10.1093/trstmh/traa178.

    PMID: 33537774
  23. 23

    Imaging of Madura foot: Case report.

    Rais A, Bouardi NE, Bouanani Z, et al.

    Radiology case reports 2024; (19(11)):4747-4750 doi:10.1016/j.radcr.2024.07.042.

    PMID: 39228927
  24. 24

    The importance of diagnostic imaging of mycetoma in the foot.

    Guerra-Leal JD, Medrano-Danés LA, Montemayor-Martinez A, et al.

    International journal of dermatology 2019; (58(5)):600-604 doi:10.1111/ijd.14351.

    PMID: 30565209

This page explains mycetoma symptoms and warning signs for informational purposes only and does not constitute medical advice. Seek prompt professional care for fever, severe pain, rapid swelling, numbness, or difficulty breathing.