CASE REPORT
Indonesia Journal of Biomedical Science (IJBS) 2026.
Volume 20.
Number 1: 12-17 P-ISSN.
E-ISSN.
Indeterminate leprosy:
case report and literature review Published by Indonesia Journal of Biomedical Science Luh Putu Venny Cempaka Sari1,2.
I Gusti Ayu Agung Dwi Karmila1,2*.
Herman Saputra2,3.
Handelia Pinari1,2.
Kevin Jonathan Djuanda1,2.
Ni Putu Wina Widyastuti1,2.
Mario Korwa1,2 ABSTRACT Background: The World Health Organization (WHO) states that Morbus Hansen (MH) or leprosy is one of seventeen neglected tropical diseases that require special global attention.
Individuals infected with leprosy but who have not yet developed a cell-mediated immune response to the organism are classified as indeterminate If left untreated, an indeterminate type of leprosy can develop into the tuberculoid or lepromatous type.
This case report aims to provide a clinical description of the indeterminate type of leprosy, to increase understanding and awareness of this condition.
Case: A 25-year-old man presented with white patches and numbness on his back for the past year, with a history of being diagnosed with leprosy at the age of 12 and completing leprosy therapy.
Physical examination revealed multiple macular patches with decreased sensitivity, without peripheral nerve thickening.
Slit skin smear examination found no acid-fast bacteria (AFB).
Histopathological examination with Ziehl-Neelsen staining found the epidermis covered by weavy keratin and perivascular lymphohistiocytic patterns, partly following the neurovascular pathway in the superficial part, without finding any AFB.
A diagnosis of indeterminate-type leprosy was established with multidrug therapy (MDT) of the paucibacillary (PB) type.
Improvement in sensitivity without skin complications was noted after completing treatment.
Conclusion: Early detection and appropriate treatment of leprosy are essential to reduce transmission of M.
to close family members, especially household contacts.
Continuous therapy and regular monitoring are crucial to improve treatment success.
Dermatology and Venereology Department.
Medical Faculty.
Universitas Udayana.
Denpasar.
Bali Ngoerah Hospital.
Denpasar.
Bali Pathological Anatomy Department.
Medical Faculty.
Universitas Udayana.
Denpasar.
Bali *Corresponding to:
I Gusti Ayu Agung Dwi Karmila.
Dermatology and Venereology Department.
Medical Faculty.
Universitas Udayana.
Denpasar.
Bali karmila@unud.
Phone: 62 819-9923-2930 Received: 2025-12-28 Accepted: 2026-02-06 Published: 2026-03-02 Keywords: Indeterminate leprosy, leprosy.
Mycobacterium leprae.
Cite this Article: Sari.
Karmila.
Saputra.
Pinari.
Djuanda.
Widyastuti.
Korwa.
Cytoreductive nephrectomy in pregnant woman with renal cell carcinoma: a case report.
IJBS 20.
: 1217.
DOI: 10.
15562/ijbs.
INTRODUCTION
HansenAos disease, also known as leprosy, is a chronic infection caused by the bacterium Mycobacterium leprae.
1,2 These bacteria can infect the mucosal skin tissue and peripheral nerves, causing loss of sensation in the skin with or without dermatological lesions.
Clinically, leprosy lesions can be macules or patches of anesthesia, or hypopigmented macules with raised and slightly erythematous edges, or erythematous infiltrates/plaques, or papules and nodules.
The WHO reported data collected from 143 countries in 2016, namely 214,783 new cases of leprosy detected and 171,948 registered cases .
revalence rate 23 per 10,000 populatio.
Of the new cases found, the highest number was in Southeast Asia .
, followed by the Americas .
Africa .
, and the rest in other regions of the world.
3,4 The prevalence rate of leprosy in Indonesia in 2023 is 0.
63 cases per 10,000 population, and the rate of new cases is 5.
2 cases per 100,000 population.
Patients with strong cell-mediated immune responses typically exhibit clinical manifestations of few lesions with low or undetectable levels of mycobacteria, and are classified as tuberculoid type.
In contrast, patients who are inactive .
to M.
leprae display lesions with higher levels of mycobacteria, and are classified as lepromatous type.
6-9 Patients who have not developed a cell-mediated immune response to the organism are classified as the Indeterminate type.
left untreated.
Indeterminate leprosy can progress to the tuberculoid or lepromatous Leprosy is one of the infectious diseases that causes very complex problems.
These problems are not only medical but also extend to social and economic issues.
Leprosy can cause disability during the course of the disease.
Delayed early detection and treatment of this disease have been linked to an increased risk of disability in the eyes, hands, and feet.
The following is a report of one case of indeterminate type leprosy in a 25-yearold male.
This case report aims to discuss the risk factors, clinical manifestations, diagnosis, and management of Leprosy, particularly the indeterminate type.
It is hoped that this case report will increase the understanding of health practitioners so that they can reduce morbidity and Open Published by Indonesia Journal of Biomedical Science | IJBS 2026.
| doi:http://ijbs-udayana.
15562/ijbs.
CASE REPORT
mortality related to the disease and underlying risk factors.
CASE
A 25-year-old male patient.
Javanese.
Indonesian citizen, came to the Dermatology and Venereology Outpatient Clinic complaining of white spots on his back accompanied by numbness for 1 The white spots first appeared on his back and then appeared on his chest and remained .
either enlarging nor There were no complaints of pain, itching, numbness in the hands and feet, or eyebrow hair loss.
The patient had a history of leprosy at the age of 12 and had completed multidrug therapy for multibacillary-type (MDT MB) children in 2011.
At that time, the patient reported white and red patches on the body accompanied by numbness and loss of sensation in the hands and feet.
After completing 12 months of treatment, the patient reported that the skin lesions had improved and there was no history of red patches or painful lumps on the The patient denied any history of other systemic diseases, drug allergies, or food allergies.
The patientAos uncle and cousin have a history of leprosy.
The patient also stated that the patientAos family lives in the same house as the patientAos The patient denied any history of other systemic diseases, drug allergies, or food allergies in the family.
Physical examination and general status were found to be within normal limits.
Dermatological status revealed multiple hypopigmented macules and patches in the anterior and posterior thoracoabdominal regions, with well-defined borders, some round and some geographic in shape, measuring 8Ae1.
6 cm and 0.
6 x 1.
2 cm Ae 1.
5 x 2 cm, were found to be discretely scattered, with a localized distribution (Figure .
Sensitivity testing revealed decreased sensation of touch, pain, and temperature in the hypopigmented patches on the Nerve examination revealed no thickening or enlargement.
Sensory testing with monofilament revealed normal results in the radial nerve, ulnar nerve, median nerve, common peroneal nerve, and bilateral posterior tibial nerve.
Voluntary muscle testing (VMT) revealed motor strength of 5 in the radial nerve.
Figure 1.
Clinical presentation during the initial visit .
anterior and posterior thoracoabdominal region, showing multiple hypopigmented macular patches.
ulnar nerve, median nerve, and bilateral posterior tibial nerve.
Skin slit smear examination revealed no acid-fast bacilli (AFB) in the right ear lobe, left ear lobe, or skin lesions.
The complete blood count, liver function, random blood glucose, and renal function results were within normal limits.
Histopathological examination of hypopigmentation patches in the posterior thoracoabdominal region.
Hematoxylin-Eosin staining revealed skin tissue consisting of the epidermis, dermis, and its adnexa, and subcutaneous The epidermis was covered by Published by Indonesia Journal of Biomedical Science | IJBS 2026.
: 12-17 | doi: 10.
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weavy keratin.
In the superficial layer, a perivascular lymphohistiocytic pattern was observed, partly following the neurovascular pathways.
No granuloma pattern was observed in this specimen.
The morphological findings showed a superficial perivascular lymphohistiocytic pattern partly following the neurovascular pathways without a granuloma.
In the Ziehl-Neelsen (ZN) histochemical stain, no acid-fast bacilli were found.
The morphological findings are consistent with indeterminate-type leprosy (Figure CASE REPORT Based on the medical history, physical examination, and supporting tests, the patient was diagnosed with indeterminatetype leprosy.
The treatment given was multidrug therapy for paucibacillarytype leprosy (MDT-PB), consisting of rifampicin 600 mg once a month and dapsone 100 mg every 24 hours intraorally, with a treatment plan for 6 months, neurotropic vitamins B1.
B6, and B12 1 tablet every 24 hours intraorally, and 10% urea cream every 12 hours topically on dry Patients were given explanations and education about the course of the disease, leprosy reactions, current treatment including its benefits and side effects, the 6-month MDT-PB treatment plan, disability and disability prevention .
heck, protect, and car.
, and contact tracing.
After 6 courses of MDT-PB treatment, there was improvement in the sensitivity of the lesions, and no leprosy reactions were Repeat slit skin smear examination showed no acid-fast bacilli (AFB).
DISCUSSION
Leprosy is a disease that attacks the skin and then develops into a secondary stage, causing peripheral neuropathy with the potential for long-term disability and This disease can cause physical disability if not treated properly, especially in productive age groups, which can interfere with functional status.
Based on epidemiological studies, leprosy is commonly found in developing countries as a result of these countriesAo limited ability to provide adequate services in the areas of health, education, and social and economic welfare to their 10,11 The global distribution of new cases of Leprosy in 2020 shows that the top five countries are, in order.
India.
Brazil.
Indonesia, the Democratic Republic of Congo, and Bangladesh.
The highest rates of detection of new cases of leprosy were also reported by countries in Africa and Southeast Asia.
Of the 127 countries that reported data in 2020.
India.
Brazil, and Indonesia reported the highest number of new cases (>10,000 9 In Indonesia itself, the reported prevalence rate of leprosy in 2023 was 0.
cases per 10,000 population, and the rate of new cases discovered was 5.
2 cases per 100,000 population.
5 In terms of gender.
Figure 2.
Histopathological examination of hypopigmentation lesions .
The epidermis is covered by weavy keratin.
In the superficial layer, there is a perivascular lymphohistiocytic pattern, partly following the neurovascular pathway.
men are more likely to develop leprosy than women.
The average male-to-female ratio globally is reported to be 2:1.
This condition can be caused by various factors, including differences in behavior and Men are associated with more outdoor activities, making them more susceptible to M.
leprae infection, while women are more accustomed to taking care of themselves and maintaining their Men pay less attention to their own health and have difficulty accessing public health services.
12,13
Regarding age, leprosy can occur in various age groups, but it is reported to be dominant in populations over 14 years of age.
14 In this case, the patient was a 25-year-old male.
The patient is of Javanese ethnicity (Jembe.
and an Indonesian According to the literature, the patient falls into the category of groups with reported cases of leprosy, with males and those over 14 years of age reported as having a higher incidence of leprosy.
Indonesia is also considered one of the countries with endemic leprosy.
leprae bacteria are obligate intracellular and aerobic.
leprae are rod-shaped, measuring 1-8 AAm x 0.
5 AAm, acid-fast (AFB) and alcohol-resistant, and are gram-positive bacteria.
1,15
Another causative agent is Mycobacterium lepromatosis (M.
, which was described in 2008 in Mexico in a patient with fatal Virchowian disseminated leprosy, and was found to have a different deoxyribonucleic acid sequence from M.
16 However, despite the considerable genetic differences between these two species, their clinical manifestations and treatments are similar, and it is only possible to distinguish between them by performing molecular testing.
17 M.
leprae reproduces more slowly than lepromatosis, with a generation time of approximately 12 to 13 days.
This indicates that M.
leprae has a long incubation period, which can range from 2 to 10 years after infection, depending on the form of the disease.
leprae shows tropism for Schwann cells, keratinocytes, and macrophages, as well as a tendency to spread more efficiently in cooler areas of the body, such as nerves near the skin surface, the skin itself, and the membranes of the upper respiratory 1 Humans are the primary carriers of M.
leprae infection.
The most common route of transmission of leprosy is through contact with droplets expelled from the upper respiratory tract of patients with multibacillary leprosy (MB).
In addition, transmission can also occur through skin contact or vertical transmission.
Published by Indonesia Journal of Biomedical Science | IJBS 2026.
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CASE REPORT
Genetic risk factors have been reported to be associated with leprosy.
In general, genetic factors influence the transmission and clinical course of leprosy.
19 Singlenucleotide (SNP) association studies indicate that the low lymphotoxin- (LTA)-producing allele is the primary genetic risk factor for early-onset leprosy.
20 SNP or other genes associated with disease and/or reaction development in leprosy are the vitamin D receptor (VDR), tumor necrosis factor (TNF)-, interleukin (IL)-10, interferon (IFN)-, human leukocyte antigen (HLA) genes, and toll-like receptor (TLR)1.
21 Associative studies have identified polymorphic risk factors in the promoter region shared by two genes, namely parkinson (PARK)-2, which encodes an E3-ubiquitin ligase called Parkin, and the parkin coregulated gene (PACRG).
A study also showed that genetic variants of nucleotide-binding oligomerization domain-containing protein (NOD)-2 are associated with susceptibility to leprosy and the development of leprosy reactions .
ype I and type II).
23 In this case, there is a possibility of a genetic factor.
This is because the patientAos uncle and cousin have a history of leprosy.
Population migration from rural areas to cities contributes to an increase in cases of leprosy, where high population density can affect poor living conditions and High density and poor hygiene can affect indoor air quality, thereby increasing the risk of transmission of leprosy, especially for people living together in one High intensity and short physical distance between people with leprosy increase the risk of leprosy.
24,25 In one systematic review study, it was reported that a history of close and prolonged contact, especially with multibacillary patients, males, and individuals over 60 years of age, is are factors that support the transmission of leprosy.
15 In addition, an individualAos immunological status greatly influences the transmission and clinical manifestation of leprosy, which is mediated by the hostAos cellular immune Leprosy has many similarities with tuberculosis, in that tissue damage is not caused solely by the bacterial agent, but also by the individualAos immune response to the M.
leprae bacteria.
24 In addition to internal factors, there are several external environmental factors that can influence the occurrence of leprosy infection.
High humidity is a condition favored by M.
Although the bacteria can survive for 9 days in dry nasal secretions.
can survive for up to 46 days in moist 24 In this case, there was a history of prolonged contact with a patient with The patient said that his uncle and cousin had a history of leprosy and that the patientAos family lived in the same house as the patientAos uncle.
Although the patient no longer lives in the same house, he said that his family visited him during the Eid al-Fitr holiday a year ago.
The two routes by which M.
leaves the human body that are often described are the skin and the nasal 1 M.
leprae is commonly found in the superficial keratin layer of the skin of lepromatous leprosy patients, indicating that the organism can be shed along with sebaceous secretions.
The number of bacilli from nasal mucosal lesions in lepromatous cases ranges from 10,000 to 10,000,000.
Nasal secretions from lepromatous patients can produce as many as 10,000,000 live organisms per day.
21 M.
leprae then enters other human bodies through direct contact with the skin or nasal mucosa originating from droplets.
After infection occurs, clinical symptoms in the peripheral nerves or skin will appear in varying degrees.
The shortest reported incubation period for leprosy is only a few This report is based on the very rare incidence of leprosy in neonates.
The maximum incubation period reported is 30 years or more.
It is generally agreed that the average incubation period for leprosy is between 3 and 10 years.
21 The clinical symptoms that arise also vary, depending on the cellular immunity of the patient.
the cellular immunity is competent, the clinical picture will be tuberculoid, whereas if the cellular immunity is impaired, the clinical picture will be lepromatous.
The clinical manifestations of leprosy can generally take the form of macules or patches of hypopigmentation with anesthesia, or hypopigmented macules accompanied by raised and slightly erythematous edges, or erythematous infiltrates/plaques, or papules and 2 There are various classification Published by Indonesia Journal of Biomedical Science | IJBS 2026.
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systems used in cases of leprosy, but the most commonly used are the World Health Organization (WHO) classification and the Ridley and Jopling classification.
Based on the WHO classification system, leprosy is categorized into two types, paucibacillary (PB) and multibacillary (MB).
The PB-type is characterized by fewer than or equal to 5 lesions, a negative bacterial index, and involvement of one nerve.
Meanwhile, the MB-type is defined as leprosy lesions on the skin that number more than or equal to 6 lesions, a positive bacterial index, or involvement of two or more nerves.
1,6 The Ridley and Jopling classification system classifies leprosy into tuberculoid leprosy (TT).
borderline tuberculoid (BT).
(BB).
borderline lepromatous (BL) and lepromatous leprosy (LL).
6,7,14 The New Indian Classification in 1981 classified leprosy into several types, indeterminate (I), tuberculoid (T), borderline (B), lepromatous (L), and polyneuritis (P).
Specifically, indeterminate-type generally occurs in patients who have not developed a cell-mediated immune response to M.
The first skin lesions that appear in the indeterminate-type are small to medium-sized hypopigmented patches, mostly located on the thighs and face, but can also be found on other parts of the body, with blurred edges and accompanied by complaints of loss of sensation.
In addition, hair growth and nerve function are not involved, so there are no common manifestations such as madarosis or peripheral nerve 8,21 In this case, the patient complained of white patches on the chest and back that appeared several years ago.
The white patches first appeared on the back and then on the chest.
The white patches were said to be persistent, neither enlarging nor shrinking.
The patient reported numbness in the white patches on the back, without itching or pain in the affected areas.
The clinical manifestations of leprosy are not limited to the skin, but can also involve the nerves.
1 The most common neurological manifestation of leprosy is peripheral nerve damage accompanying skin lesions, especially in the skin nerve fibers and nerve trunks.
The pattern and distribution of nerve damage are CASE REPORT influenced by the number of bacteria infiltrating the nerves, as well as the patientAos immunological response to the infected nerves.
Based on this, the clinical manifestations of peripheral nerve damage can be classified into sensory disorders, motor disorders, and autonomic disorders.
7,9 Leprosy generally involves the superficial nervous system, such as the auricularis magnus, medianus, ulnaris, sural, posterior tibialis, and superficial peroneal nerves.
10 In this case, sensitivity examination revealed a decrease in touch, pain, and temperature sensation in the hypopigmented patches on the back.
Nerve examination did not reveal any thickening or enlargement.
Sensory examination with monofilament and motor examination with VMT were within normal limits in the radial nerve, ulnar nerve, median nerve, and bilateral posterior tibial nerve.
A diagnosis of leprosy can be made if the following criteria are met: .
hypopigmented or erythematous skin lesions or red patches of skin with loss of sensation.
thickened or enlarged peripheral nerves with loss of sensation and/or weakness of the muscles innervated by those nerves.
skin smears showing acid-fast or bacilli observed in skin smears/biopsies.
The presence of all three criteria indicates a diagnostic accuracy of 95%.
7,26 Various tests can be useful in confirming the diagnosis of These tests include measuring antibody titers against Mycobacterium antigens with rapid lateral flow devices.
cell-mediated cytokine release assays .
uch as IFN- detection, similar to commercial complete blood tests used to detect infection by M.
amplification of Mycobacterium DNA with polymerase chain reactions (PCR).
or the use of metabolomics to detect molecular features specific to M.
leprae infection in blood or urine.
1 Histopathological examination with skin biopsy can be performed to confirm the diagnosis of Skin biopsies should include the dermis layer and, if possible, extend to the subcutaneous layer of the lesion.
Hematoxylin-eosin be supplemented with the Fite-Faraco staining method or another method to detect acid-fast bacilli.
However, there are differences in establishing a diagnosis of indeterminatetype leprosy.
Specifically, in indeterminate leprosy, the diagnosis is confirmed by biopsy showing perineurovascular infiltration.
Acid-fast bacilli are not commonly found on histopathological examination.
9,27
Other include focal, perivascular, perianaxial, inflammatory infiltrates.
In the lepromin test, indeterminate-type leprosy will show a negative result, so it is considered PB type for treatment purposes.
27 In this case, a slit skin smear examination showed no acidfast bacilli (AFB) in the right ear lobe, left ear lobe, or skin lesions.
Histopathological examination with Hematoxylin-Eosin
staining showed superficial perivascular lymphohistiocytosis partially following the neurovascular pathway without Ziehl
Neelsen
(ZN)
histochemical staining did not reveal acidfast bacilli.
The morphological findings were consistent with indeterminate-type The includes pharmacological and nonpharmacological Pharmacological therapy includes MDT recommended by the WHO to treat leprosy based on the PB and MB-types.
For treatment purposes, indeterminatetype leprosy is considered PB-type based on lepromin test results.
27 There are three MDT options that are currently available:
for PB-type (MDT-PB) and MB type (MDT-MB).
The adult MDT-PB package for single lesions includes rifampicin 600 mg plus ofloxacin 400 mg, and minocycline 100 mg (ROM) single dose.
The adult MDT-PB package consists of rifampicin 600 mg and dapsone 100 mg taken once a month under supervision and dapson 100 mg once a day taken independently.
Six packages are given, to be completed within 6-9 months.
In general.
MDT containing rifampicin has a bactericidal mechanism of action, while other anti-leprosy drugs are bacteriostatic.
6,22 In this case, the patient was given multidrug therapy for paucibacillary-type (MDT PB) package and completed the 6-month treatment The clinical course of leprosy is associated with the development of disabilities, particularly in the eyes, hands, and feet, affecting both soft tissue and bone, which leads to disability and deformity.
Leprosy also causes social stigma.
1,8-12
However, in indeterminate-type leprosy, it has been reported that approximately 75% of lesions heal spontaneously.
Additionally, the prognosis for this type of leprosy is very good, and leprosy reactions have never been reported.
8 In this case, the Mycobacterium species was not examined through PCR testing.
However, this case was traced through histopathological examination until the completion of CONCLUSION Indeterminate-type of leprosy is an early form of leprosy that is not yet stable, characterized by pale white patches .
or redness on numb skin, often appearing in people with compromised immunity, and can heal spontaneously or develop into another type of leprosy depending on the bodyAos immune response.
Although it often heals on its own, early diagnosis and treatment with MDT-PB for 6 months is considered better to prevent this type of leprosy from progressing to tuberculoid or lepromatous CONFLICT OF INTEREST There is no conflict of interest on the part of the author regarding the publication of this case report.
ETHICS IN PUBLICATION
The patient has received information and signed an informed consent form to use the patientAos medical information and clinical photographs for educational and scientific publication purposes.
FUNDING
There was no funding sponsorship for the care, examination, and treatment of patients, nor for the publication of this case report.
AUTHORS CONTRIBUTION
The LPVCS author is responsible for patient examination, care, and Published by Indonesia Journal of Biomedical Science | IJBS 2026.
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CASE REPORT
treatment, as well as literature review and manuscript preparation.
The IGAADK author is responsible for publication correspondence.
The HS author is responsible for supervising The authors of the HP.
KJD.
NPWW, and MK are responsible for patient care.
GENERATIVE AI DISCLOSURE
There is no usage of artificial intelligence (AI) in the manuscript preparation.
REFERENCES