Mycobacterium avium infection of the skin associated with lichen scrofulosorum: report of three cases

Tuberculids: A Narrative Review

Tuberculids are a group of dermatoses with tuberculoid histology and the absence of tubercle bacilli. They are considered to be hypersensitivity reactions to circulating Mycobacterium tuberculosis (M. tb) or its antigens in individuals with good immunity. The objective of the review is to provide a detailed literature review of all available articles on tuberculids in the past 10 years and provide an update on epidemiology, etiopathogenetic mechanisms, clinical manifestations, and treatment. A search was performed on PubMed using the keywords lichen scrofulosorum, papulonecrotic tuberculid, erythema induratum, and erythema nodosum tuberculosis for all articles, with no restrictions on age, gender, or nationalities. An update on tuberculids, including some new concepts in pathogenesis, atypical presentations, new investigative modalities, and treatments are reviewed.

Septic arthritis of native joints due to Mycobacterium avium complex: A systematic review of case reports

INTRODUCTION

While MAC native joint septic arthritis is historically considered a rare entity, the number of reported cases have increased in recent decades. However, no comprehensive review of this topic has been conducted.

OBJECTIVES

To conduct a systematic review of cases of MAC native joint septic arthritis reported in the literature and summarize the presentations, baseline characteristics, risk factors, diagnosis, treatment, and treatment outcomes.

METHODS

A systematic review was conducted by performing an extensive literature search through Medline, Google Scholar, and Web of Science, starting from their inception. Screening of articles, assessment of eligibility, and data synthesis from eligible articles were independently performed by two reviewers with input from a third reviewer to achieve consensus. Inclusion criteria to determine eligibility included articles in English, case reports/case series, adult patients who presented with MAC/MA/MI septic arthritis of a native joint. Statistical analyses were performed using Statistical Package for the Social Sciences.

RESULTS

Thirty-three cases of MAC native joint septic arthritis were reported since 1976. MAC septic arthritis affects immunocompetent and immunocompromised patients, most frequently as a monoarthritis involving the knees and wrist. MAC septic arthritis may present in the context of disseminated MAC infection and primary MAC septic arthritis. The average time to diagnosis from onset of symptoms was 20 months, where the majority of cases were initially misdiagnosed. Although arthrocentesis can be used to make the diagnosis, a synovial biopsy is necessary in many cases to confirm the diagnosis. A combination of surgery and antimycobacterial drug treatment has the highest chance of achieving complete resolution.

CONCLUSION

The diagnosis of septic arthritis of native joints due to MAC can be challenging and/or delayed. A high level of suspicion is needed in high-risk patients and also when atypical presentations occur. Therefore, understanding the presentation, risk factors, and pitfalls in diagnosing MAC septic arthritis are essential. MAC septic arthritis literature is scarce, necessitating further research of this rare condition to increase awareness, diagnostic accuracy and determine the optimal treatment strategy to improve patient outcomes.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.

Psoriasiform type of lichen scrofulosorum: clue to disseminated tuberculosis

We present a 16-year-old girl with tuberculosis of the lungs, lymph nodes, and liver, who had extensive inflammatory lesions with pustules, which resembled psoriasis. A skin biopsy showed extensive tuberculoid granulomas surrounding hair follicles, consistent with lichen scrofulosorum. Antitubercular therapy led to resolution of skin lesions. This severe inflammatory type of lichen scrofulosorum is extremely rare.

Mycobacterial spindle cell pseudotumor of the skin

BACKGROUND

Mycobacterial spindle cell pseudotumor is a rare tumor-like lesion characterized by the proliferation of spindle cells engorged with mycobacterial microorganisms. To our knowledge, only a few cases of cutaneous lesions have been described in the literature.

CASE REPORT

A 58-year-old Japanese woman presented with a nodule in her left forearm. She had systemic lupus erythematosus and interstitial pneumonia for 17 years, treated with prednisolone and azathioprine. She was also receiving insulin treatment for diabetes mellitus.

RESULTS

Histologically, the lesion was located in the deep dermis with extension into the subcutaneous fat tissue and was composed mainly of spindle cells focally showing a vaguely storiform pattern. In limited focal areas, foam cells, epithelioid histiocytes, and multinucleated giant cells were seen sparsely. Ziehl-Neelsen staining showed numerous acid-fast bacilli within the spindle cells and epithelioid histiocytes. The acid-fast bacilli were determined by culture and polymerase chain reaction to be Mycobacterium intracellulare.

CONCLUSIONS

We emphasize that mycobacterial spindle cell pseudotumor should be included in the differential diagnoses of a spindle cell lesion in the skin, especially in immunosuppressed patients.

Caso para diagnóstico

As tubercúlides são reações cutâneas imunológicas à presença de tuberculose, que com freqüência se encontra oculta no organismo. Antigamente um grande número de lesões cutâneas era interpretado como tubercúlide. Atualmente, porém, apenas três entidades são consideradas verdadeiras tubercúlides: tubercúlide papulonecrótica, eritema indurado e o líquen scrofulosorum. Pacientes com líquen scrofulosorum apresentam forte reação ao teste de Mantoux e excelente resposta aos tuberculostáticos.

Lichen scrofulosorum: A prospective study of 39 patients

BACKGROUND

Lichen scrofulosorum is considered a rare form of cutaneous tuberculosis. Current information is based on case reports and case series with a small number of patients.

METHODS

Thirty-nine patients with Lichen scrofulosorum were followed during the period January 1996 to December 2002. Clinical details (age, sex, duration of disease, associated tubercular lesions, extent and distribution of skin lesions), laboratory parameters (hemoglobin, total leucocytic counts, erythrocyte sedimentation rate, Mantoux test, presence of BCG scar), and response to antitubercular treatment were recorded and analyzed.

RESULTS

7.6% patients of all (511) patients with cutaneous tuberculosis had LS. 22 (56.4%) were males and 32 (84%) were below 15 years of age. Twenty-eight (72%) had an associated focus of tuberculosis elsewhere in the body; 13 (33%) had tubercular lymphadenopathy, while 11 (28%), three (8%) and six (15%) had pulmonary tuberculosis, intracranial tuberculosis and other forms of cutaneous tuberculosis, respectively. Six (15%) had tubercular focus at multiple sites. Eleven (28%) had no other identifiable focus of tuberculosis. Twenty-eight (72%) had evidence of receiving BCG vaccination. Trunk was the commonest (100%) affected site. The two groups with and without associated tubercular focus were not different with respect to age, sex, duration of disease, hemoglobin, total leukocyte count, erythrocyte sedimentation rate, Mantoux test positivity, and presence of BCG scar. Mycobacteria tuberculosis could not be detected either on acid fast bacilli (AFB) staining or on culture from biopsies of LS lesions. All patients (including those without evidence of tubercular focus) responded to antitubercular treatment, signifying an underlying occult tubercular focus as etiology.

CONCLUSIONS

Lichen scrofulosorum is an uncommon but not rare cutaneous manifestation of tuberculosis. A high index of suspicion and awareness is required for diagnosis. Systemic tuberculosis is often associated with LS and a prior BCG inoculation does not protect against development of LS. Response to antitubercular treatment is good irrespective of the presence or absence of associated tubercular focus.

Lichen scrofulosorum: a rare manifestation of a common disease

Tuberculids develop as hypersensitive immunologic reactions in the skin to an occult internal focus of tuberculosis. These eruptive lesions are due to hematogenous dissemination of bacilli in a host with a high degree of immunity against Mycobacterium tuberculosis. Although rare, these specific lesions are important diagnostic markers of tuberculosis. Lichen scrofulosorum is one of the recognized tuberculids, usually seen in children and young adults. We report three children with lichen scrofulosorum; in two children it developed during treatment of tuberculosis. The appearance of lichen scrofulosorum after initiation of treatment due to a probable increase in cell-mediated immunity is emphasized.

Rapid identification of cutaneous infections by nontubercular mycobacteria by polymerase chain reaction-restriction analysis length polymorphism of the hsp65 gene

BACKGROUND

Nontubercular mycobacteria (NTM) may cause cutaneous infections which are difficult to interpret due to the variability of the clinical manifestations. This study involved eight patients (four men and four women) with primary cutaneous infections caused by NTM; the skin lesions included dermo-hypodermal abscesses, suppurative granulomas, and papulonodules localized on the legs, arms, hands, and face. The general condition of the patients was relatively good and they were not immunosuppressed.

METHODS

All samples were processed with standard methods and the isolates were identified by pattern restriction analysis after polymerase chain reaction (PCR-PCA) amplification of the heat shock protein of 65 kDa.

RESULTS

In this way, we were able to identify three Mycobacterium chelonae strains, two Mycobacterium marinum, two Mycobacterium fortuitum, and one Mycobacterium avium. The lesions disappeared in 3 or 4 weeks after treatment with two or more antimicrobials.

CONCLUSIONS

For a correct diagnosis of cutaneous infection by NTM, demonstrating the presence of mycobacteria is essential; routinely available techniques lack sensitivity and are extremely tedious; often mycobacteria are not seen after acid-fast stain. We used PCR-PCA to identify mycobacteria grown in liquid media; the time of identification of mycobacteria was shortened relative to conventional methods.