Polymerase chain reaction compared to other laboratory findings and to clinical evaluation in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection

Natural mycobacterium tuberculosis complex infection in a brown howler monkey (Alouatta guariba clamitans) in Brazil

Neotropical primates rarely exhibit active tuberculosis. A brown howler monkey was found injured in an urban area. Histopathology revealed granulomatous inflammation in the lungs, lymph nodes, and liver. Immunohistochemistry and molecular analysis confirmed the presence of Mycobacterium tuberculosis complex. The findings highlight the importance of TB surveillance in nonhuman primates.

DNA microarray chip assay in new use: early diagnostic value in cutaneous mycobacterial infection

Introduction

The clinical practicability of DNA microarray chip in detecting the presence of mycobacterial species/isolates directly in the skin tissues has not been evaluated, nor the efficacy of DNA microarray chip as a novel diagnostic tool for the early diagnosis of cutaneous mycobacterial infections is known.

Methods

The present study analyzed the incidence of cutaneous mycobacterial infections in Shanghai and explored the efficacy of a novel DNA microarray chip assay for the clinical diagnosis of the disease from skin tissue specimens compared to traditional detection methods. A total of 60 participants fulfilling the defined diagnostic criteria and confirmed positive for cutaneous mycobacterial infections from 2019 to 2021 were enrolled in the study. Subsequent to recording the participants' medical history and clinical characteristics, the skin tissue specimens were collected for analyses. The specimens underwent histopathological analyses, skin tissue culture, and DNA microarray chip assay.

Results

Increased incidence of cutaneous mycobacterial infection was detected from 2019 to 2021. The most common infecting pathogen was M. marinum followed by M. abscessus. The sensitivity, specificity and accuracy of the skin tissue culture method were 70%, 100% and 76.62%, respectively, while that of the DNA microarray chip assay were 91.67%, 100% and 93.51%, respectively. The sensitivity and accuracy of the DNA microarray chip assay were significantly higher than those of the skin tissue culture method. The positive likelihood and diagnostic odds ratio were >10 and >1, respectively for both the methods. The negative likelihood ratio was significantly higher (30% vs 8.33%) and the Youden's index was significantly lower (70.00% vs 91.67%) in the skin culture method compared to that of the DNA microarray chip assay. There was a significant association of false negative results with a history of antibiotic use in the skin tissue culture method.

Discussion

Given the increasing incidence of cutaneous mycobacterial infections, early diagnosis remains a prime clinical focus. The DNA microarray chip assay provides a simple, rapid, high-throughput, and reliable method for the diagnosis of cutaneous mycobacterial infections with potential for clinical application.

Multiple diagnostic examinations are effective for the early diagnosis of scrofuloderma

Although scrofuloderma is the most common subtype of cutaneous tuberculosis, its diagnosis is often delayed. In this case, ciprofloxacin was first administered as only Pseudomonas aeruginosa was detected by initial culture tests. Mycobacterium tuberculosis is usually susceptible to quinolone antibiotics, hence the partial improvement in inflammatory symptoms and subsequent delay in diagnosis. Our case serves as a reminder that we should always be aware of the possibility of cutaneous tuberculosis being the cause of an abscess, especially when the abscess is not completely resolved by antibiotics. Moreover, our case reminds us that it is necessary to conduct repeated culture tests, rather than relying purely on polymerase chain reaction (PCR) results, given that cases of PCR-negative acid-fast bacilli (AFB) culture-positive scrofuloderma have been reported. Fine needle aspiration is a less invasive and useful way to collect culture samples.

Diagnostic Dilemma of Cutaneous Tuberculosis: Opening of the Pandora's Box

ABSTRACT

Tuberculosis in all forms, that is, pulmonary (PTB) or extrapulmonary (EPTB), is a universal health problem. Cutaneous tuberculosis (CTb) remains one of the least studied and often under-reported variants of EPTB because of its wide and protean clinical presentation. The diagnosis of CTb remains challenging because of lack of sensitive and specific investigations for its diagnosis. The sensitivity of some of the traditional tests is low because of low concentration of mycobacteria in paucibacillary lesions. Besides it is difficult to distinguish between M. tuberculosis (MTb) and other mycobacterial species in skin biopsies morphologically. Molecular methods may target either MTb DNA or RNA, and serve as promising tools in the diagnosis of various forms of CTb, with high sensitivity and rapidity. This review is focused on diagnostic challenges of CTb and to discuss various methods and newer technologies for diagnosing CTb. This will help the dermatologists and dermatopathologists to elucidate and accurately diagnose CTb from other infectious granulomatous dermatitis for appropriate timely treatment of the patient.

Mycobacterial Infections in the Hand and Wrist

Mycobacterial hand infections are uncommon. These infections have an indolent course and are marked by variable and nonspecific presentations, often leading to diagnostic and treatment delays. The pathogens involved in mycobacterial hand infections include Mycobacterium tuberculosis complex, atypical mycobacteria, and M leprae. Initial treatment involves a combination of long-term antibiotics and surgical débridement to cure the infection. Reconstructive procedures aid in restoring hand function lost secondary to the disease.

Comparisons between fresh and cryopreserved fat injections in facial lipofilling

Background

Autologous fat is considered an ideal filler material, and the use of cryopreserved fat grafts is promising in terms of flexibility and efficiency. Therefore, cryopreserved fat grafts have become more common in recent years; however, their complications require further consideration.

Methods

We evaluated 53 patients who underwent facial lipofilling at our institution to confirm the clinical usefulness and safety of cryopreserved fat. Fresh fat injections with or without cryopreserved fat were administered. At one or more sites, 22 patients had a single fresh fat injection, four patients had two or more fresh fat injections, 16 patients had one fresh fat injection followed by one cryopreserved fat injection, six patients had one fresh fat injection followed by two cryopreserved fat injections, and five patients had two fresh fat injections and one or more cryopreserved fat injections.

Results

In total, 281 sets of injection procedures were performed at various sites, of which 170 involved one fresh fat injection, 89 involved one fresh fat injection and one cryopreserved fat injection, and 11 involved one fresh fat injection and two cryopreserved fat injections. One patient experienced self-resolving inflammation as a complication after the second injection in the right cheek. No statistically significant differences were found between the fresh and cryopreserved fat injections.

Conclusion

We suggest that cryopreserved fat is a useful and safe resource for multiple fat injections, with advantages including aseptic fat handling and the delicacy of the technique.

Diagnosis of mycobacterial skin infections

The diagnosis of cutaneous mycobacterial infections may be challenging. Owing to the broad spectrum of their clinical presentations, mycobacterioses have to be considered as differential diagnoses to many inflammatory dermatoses. Diagnostic measures comprise histology including special staining, cultures and molecular microbiological examinations as well as the detection of cellular immune reactions of the patient by means of interferon-γ release assays and skin testing. Clinicians should know the appropriate use and combination of procedures to diagnose mycobacterioses quickly and correctly and to avoid costs and delays caused by unnecessary examinations. This mini review summarizes advantages, limitations, and pitfalls of diagnostic methods for mycobacterial skin infections.

Cutaneous Tuberculosis: Clinicopathologic Arrays and Diagnostic Challenges

The clinicopathological manifestations of cutaneous tuberculosis are diverse. The precise diagnosis is often overlooked, due to clinical presentations as those of cutaneous diseases with different etiology and the relative paucity of the pathogens in the lesions. Meanwhile, almost all of the diagnostic methods confer lower sensitivity and specificities which augments further diagnostic challenges. This article revises the current scenario of the disease's physiopathology and underscores clinicopathological challenges, due to multifaceted presentations of cutaneous tuberculosis, in the diagnosis.

Keim oder kein Keim: Herausforderungen bei der Diagnose mykobakterieller Infektionen der Haut

Kutane Mykobakteriosen sind in Deutschland selten. Dennoch ist es für eine frühzeitige Diagnose und anschließende wirksame Behandlung erforderlich, dass diese Krankheitsbilder im ärztlichen Bewusstsein verankert sind. Darüber hinaus stehen Infektionen mit Mykobakterien auf der Liste der Differentialdiagnosen vieler Hautkrankheiten. Diagnosen kutaner Mykobakteriosen beruhen auf klinischen Merkmalen und auf Laboruntersuchungen, einschließlich bakterieller Kulturen, histopathologischer Untersuchungen und PCR-basierten Verfahren. Das Wissen um Möglichkeiten und Grenzen dieser Laboruntersuchungen ist von zentraler Bedeutung, um eine angemessene klinische Entscheidung zu treffen. In diesem Beitrag diskutieren wir die aktuellen diagnostischen Möglichkeiten, die in Verdachtsfällen kutaner Mykobakteriosen zur Verfügung stehen.

Treatment of the Mycobacterium chelonae Infection after Fat Injection

For recent years, use of autologous fat injection has increased significantly in facial contouring surgery. Along with such increase in use, complications like atypical mycoplasma infection have been also on the increasing trend. The authors report two cases of Mycobacterium chelonae infection that occurred after autologous fat injection. Patients were treated as infection that resistant to common antibiotics and results were negative to routine culture and Gram staining. Acid-fast bacillus stain, polymerase chain reaction (PCR) test and mycobacterial cultures were conducted for diagnosis under suspicion of atypical mycoplasma infection. Then, combination antibiotics therapy, surgical treatment, and steroid injection were performed for treatment. Both patients were diagnosed with Mycobacterium chelonae in PCR test. They were positive to mycobacterial cultures. Combination antibiotics therapy was repeated to improvement of symptom. However, they could not be free from side effects such as deformation in facial contour, scar and pigmentation even after full recovery. When chronic wound infections after autologous fat injection, we must suspect atypical or mycobacterial infection and conduct examinations for a early diagnosis and proper antibiotic therapy that is effective to the nontuberculous mycobacteria.

Cutaneous tuberculosis: diagnosis, histopathology and treatment - part II

The evolution in the knowledge of tuberculosis' physiopathology allowed not only a better understanding of the immunological factors involved in the disease process, but also the development of new laboratory tests, as well as the establishment of a histological classification that reflects the host's ability to contain the infectious agent. At the same time, the increasing bacilli resistance led to alterations in the basic tuberculosis treatment scheme in 2009. This article critically examines laboratory and histological investigations, treatment regimens for tuberculosis and possible adverse reactions to the most frequently used drugs.

Lewandowsky's Rosaceiform Eruption: a Form of Cutaneous Tuberculosis Confirmed by PCR in Two Patients

Introduction

Cutaneous tuberculosis (TBC) is a chronic disease caused by Mycobacterium tuberculosis, and is present in less than 1–2% of all TBC cases. The current problem with diagnosis is the demonstration of bacillus in the skin, especially paucibacillar forms, where sources like polymerase chain reaction (PCR) have improved diagnostic capacity.

Case Presentation

Two cases of cutaneous TBC are reported. The first patient was 52-year-old woman with facial erythematous papulo-nodular lesions which had been developing for 4 months, and had previously been treated as acne rosacea, with partial response. Histopathological studies showed chronic granulomatous inflammation. TBC was suspected, so PCR was performed, which showed positive for M. tuberculosis. The second case was a 43-year-old woman with a facial rosaceiform plaque which began 6 months previously, and was treated as rosacea without any change for 5 months. Skin biopsy and PCR were positive for TBC. Both cases were treated using primary schedule for TBC, and both presented a favorable response.

Discussion

A clinical profile called Lewandowsky’s rosacea-like eruption has been previously described. The condition has been questioned for years and was later removed from the spectrum of tuberculids and cutaneous TBC for not being able to isolate microorganisms in skin samples, a situation that might now change. In paucibacillar forms, when culture and staining are negative and TBC is still suspected, it is recommended to use DNA amplification by PCR for an accurate diagnosis. Both cases bring up the concern about once again bringing Lewandowsky’s rosaceiform eruption into the spectrum of cutaneous TBC, and the discussion about the current definition of tuberculid.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0066-x) contains supplementary material, which is available to authorized users.

Mycobacterium smegmatis in skin biopsy specimens from patients with suppurative granulomatous inflammation

Formalin-fixed, paraffin-embedded skin biopsy specimens, including 72 suppurative granulomatous inflammation (SGI) and 47 non-SGI controls, were tested for mycobacteria by using a broad-range PCR and a suspension array identification system. Mycobacterium smegmatis was detected in 13 (18.1%) of the SGI skin biopsy specimens, which was significantly more than 2 (4.3%) in the controls (odds ratio, 5.73; 95% confidence interval, 1.21 to 27.06; P = 0.028).

Diagnosis of extrapulmonary tuberculosis by PCR

During the last two decades, the resurgence of tuberculosis (TB) has been documented in both developed and developing nations, and much of this increase in TB burden coincided with human immunodeficiency virus (HIV) epidemics. Since then, the disease pattern has changed with a higher incidence of extrapulmonary tuberculosis (EPTB) as well as disseminated TB. EPTB cases include TB lymphadenitis, pleural TB, TB meningitis, osteoarticular TB, genitourinary TB, abdominal TB, cutaneous TB, ocular TB, TB pericarditis and breast TB, although any organ can be involved. Diagnosis of EPTB can be baffling, compelling a high index of suspicion owing to paucibacillary load in the biological specimens. A negative smear for acid-fast bacilli, lack of granulomas on histopathology and failure to culture Mycobacterium tuberculosis do not exclude the diagnosis of EPTB. Novel diagnostic modalities such as nucleic acid amplification (NAA) can be useful in varied forms of EPTB. This review is primarily focused on the diagnosis of several clinical forms of EPTB by polymerase chain reaction (PCR) using different gene targets.

Changing the way we diagnose tuberculids with interferon gamma release assays

Diagnosing tuberculids traditionally requires clinicopathological correlation together with positive tuberculin skin tests (TST) or demonstration of Mycobacterium tuberculosis (MTB) DNA by polymerase chain reaction (PCR). Interferon gamma release assays (IGRA) are new laboratory tests approved for the diagnosis of MTB infection. We describe three patients with tuberculids who had no other clinical feature of tuberculosis (TB) infection and negative PCR of skin biopsies. Their diagnoses were aided by positive IGRA.

Diagnostic procedures in dermatology

Although most skin diseases can be diagnosed with simple visual inspection, laboratory investigations are necessary in several clinical circumstances. This contribution highlights the usefulness of routine diagnostic procedures that are often overlooked and the innovative methods of molecular biology, which are expensive and require an experienced staff. Among the classic diagnostic investigations are (1) the use of Wood's light in many dermatologic disorders (eg, vitiligo, pityriasis versicolor, erythrasma, porphyrias), (2) cytodiagnosis of Tzanck in dermatologic practice (eg, herpetic infections, molluscum contagiosum, leishmaniasis, pemphigus vulgaris, basal cell carcinoma, erythroplasia of Queyrat, Hailey-Hailey disease), and (3) microscopic examination for fungal and bacterial skin infections as well as for mite infestation using potassium hydroxide, simple saline, and Gram stain. Modern molecular biotechnologies encompassing gene-specific polymerase chain reaction and its variants have a substantial affect in selected cases of viral (especially herpes simplex virus), bacterial, fungal, and protozoan (Leishmania) skin infections.

[Infections due to Mycobacterium marinum: a review]

Mycobacterium marinum belongs to the non-tuberculous or "atypical" mycobacteria. The reservoirs for these ubiquitous and slowly growing bacteria are both fresh water and salt water. In particular, aquaria should be considered as important source of hobby-related infections especially of fingers, hands and forearms. Affected are both immunosuppressed patients and persons with an intact immune system. Distinctive are erythematous plaques and nodules with tendency for hyperkeratosis, crusting, and superficial ulcerations, sometimes as sporotrichoid lymphocutaneous infection. The histology shows non-caseation granulomas containing epithelioid cells and Langhans giant cells. Using the Ziehl Neelsen staining, typical acid-fast rods are not always detectable. The molecular biological detection of mycobacterial DNA using polymerase chain reaction represents the standard method of diagnosis. Cryotherapy is frequently used as first treatment. For the often long-term tuberculostatic therapy, rifampicin, ethambutol, and clarithromycin are the most used agents.

Simultaneous scrofuloderma and intracranial tuberculomas: a rare presentation of systemic tuberculosis

Tuberculosis can involve multiple organ systems concurrently. We report a case of simultaneous brain tuberculomas and scrofuloderma occurring in the same patient. Skin biopsies confirmed scrofuloderma and the patient was successfully treated for tuberculosis with resolution of the brain masses. This case illustrates the importance of dermatological manifestations of systemic disease as an accessible source for diagnosis and guidance in appropriate therapy.

Modified fine-needle aspiration technique for diagnosis of granulomatous skin lesions with special reference to leprosy and cutaneous tuberculosis

Skin infections are commonly assessed by slit skin or scrape methods. Fine-needle aspiration biopsy (FNAB) is highly effective especially with blanching of skin to ensure good yield and reduced bleeding. The aim of this study was to assess usefulness of cytology, especially modified FNAB technique, in diagnosis of leprosy and cutaneous tuberculosis and to identify specific cytological characteristics for diagnosis and classification. The study was conducted on 40 patients-25 cases of leprosy and 15 cases of cutaneous tuberculosis. Smears were prepared using modified FNAB technique, slit skin, and scrape methods (depending on type of lesion). Cytological diagnosis was confirmed by histopathology where the Ridley-Jopling system was used to classify cases of leprosy. A similar attempt was made for diagnosis and classification of leprosy on cytology. Diagnoses rendered by both modalities were compared to assess the efficacy of cytological examination. Cytological diagnosis was made in 23 cases of leprosy and 12 cases of cutaneous tuberculosis. The smears showed good cellularity. A broad division into tuberculoid and lepromatous leprosy could be made fairly accurately on cytology. Maximum agreement among clinical, cytological, and histopathological diagnosis was observed in cases of tuberculoid leprosy. Smears of cutaneous tuberculosis were characterized by epithelioid cell granulomas with caseation. Overall accuracy of diagnosis was 92% in leprosy and 80% in tuberculosis. FNAB is an inexpensive and accurate procedure for diagnosis of leprosy and cutaneous tuberculosis. The modified technique yields good results. However, clinical correlation, acid-fast staining, and culture are essential as they provide valuable supportive information.

Giant verrucous nodules in a patient with tuberculosis

Sarcoidosis is a systemic inflammatory disorder characterized histologically by noncaseating granulomas in affected organs. Cutaneous manifestations of the disease such as papules, nodules, plaques, and ulcerations occur in approximately 25% of the patients. Sarcoidosis can present with multiple different morphologies including annular, psoriasiform, ichthyosiform, morpheaform, and verrucous. In this study, we report a 30-year-old African American man with a history of spinal tuberculosis as a child and slowly enlarging verrucous nodules that appeared at the age of 5 years. After an extensive infectious disease evaluation, the diagnosis of verrucous sarcoidosis was established with the presence of noncaseating granulomas and a completely negative workup for infectious etiologies.