Nodular lymphangitis due to nocardiosis

Abstract

Nodular lymphangitis is an infectious disease characterised by the development of inflammatory skin nodules that follow the direction of lymphatic drainage. We present a woman in her 70s with nodular lymphangitis that developed after mild trauma with a cactus. Surgical intervention was performed on a finger abscess with isolation of Nocardia brasiliensis in the microbiological samples. Initial antibiotherapy was modified, treating with cotrimoxazole, firstly intravenous and finally oral, therapy during 3 months with a complete resolution of the infection.

Background

Nodular lymphangitis is an infectious disease characterised by the development of inflammatory skin nodules that follow the direction of lymphatic drainage.¹ The skin lesions that these patients shows after trauma are typically caused by Sporothrix schenckii, nocardia or micobacterias. Although the epidemiology, symptoms and the type of skin lesion can help guide the diagnosis, it is important to take samples to confirm its aetiology. Cutaneous nocardiosis is one of the infectious agents that have to be considered.²

We present this case because of its interesting differential diagnosis, including different infectious agents, each of which has a different treatment. It is important to start the proper empiric antibiotic coverage until we confirm our suspected diagnosis with the culture of the lesion.

Case presentation

A woman in her 70s came to the emergency department because of pain and inflammation in the first finger of her left hand. As a clinical background, she was diagnosed of multiple myeloma IgG lambda stage 2 IPI 2, for which she had received six cycles of Velcade-lenalidomide-dexamethasone with pamidronate with subsequent complete remission, continuing with pamidronate until completing 24 months of treatment. She had haematology follow-ups and had been 6 months free of illness without treatment. She had toxic polyneuropathy and chronic diarrhoea as a side effect of the haematological treatment.

The symptoms had started after pricking herself with a cactus the previous week.

During this time, she had been treated with amoxicillin without any improvement. The lesion had progressed and she decided to go to the hospital for evaluation. She denied fever or dysthermic sensation, and any other symptoms in the rest of the anamnesis. When she arrived at the emergency department, the patient was haemodynamically stable, in good general condition and without fever. On the left hand, at the level of the first finger, a wound of about 0.5 cm in diameter that drained purulent content was observed. In addition to this, she had an erythematous plaque on the forearm with three nodules (figure 1). The rest of the physical exploration was normal.

Figure 1.

Erythematous plaque on the forearm.

Laboratory tests showed elevated reactants, with a C reactive protein of 59 mg/L (0–5) without leucocytosis or other relevant findings. A chest X-ray was performed, which was normal, and a Doppler ultrasound of the left arm revealed findings that suggested cellulitis. Surgical intervention was performed taking microbiological samples of the finger abscess (figure 2). Antibiotic therapy with vancomycin and cloxacillin was prescribed and changed 2 days after to ceftriaxone and clindamycin due to progression of the lesion (figure 3) and an increase in reactants. Itraconazole was added because sporotrichosis was suspected.

Figure 2.

Finger abscess after surgical intervention.

Figure 3.

Forearm injury progression.

Differential diagnosis

Nodular lymphangitis, also called sporotrichoid lymphocutaneous infection, is an infectious entity caused by different micro-organisms, including Sporothrix schenckii, Mycobacterium marinum, leishmaniasis and Nocardia brasiliensis, among others. Most of the lesions affects the extremities.¹ Clinical and epidemiological aspects like travel, work, exposure to animals or certain activities, are important for a first diagnostic approach. In the presence of a traumatic injury, it will guide the picture to sporotrichosis, nocardiosis or mycobacteria; contact with water is frequent in M. marinum; exposure to animals such as cats or dogs is typical of sporotrichosis, nocardiosis or blastomycosis; tularaemia is frequent in exposure to ticks or hunting. The incubation time is also important, short periods of less than a week orient to a bacterial cause, while longer periods of two or more weeks point to other pathogens. Depending on the infectious agent that cause the disease, the clinic may vary. The presence or absence of pain and suppuration at the level of the lesion, its morphology and systemic symptoms (fever, headache, myalgia) can make us focus in different pathogens.² For example, S. schenckii normally is a painless ulcerated nodule without suppurative granulomas, M. marinum has a midly tender, often ulcerated nodule with scant seropurulent exudate, and N. brasiliensis has tender nodules commonly ulcerated with purulent drainage.¹ In the end, the culture and histopathological study of the lesion is going to confirm the aetiological diagnosis.²

Outcome and follow-up

A few days later microbiology department notified the isolation of N. brasiliensis in the culture (figure 4). Antibiotherapy was adjusted, starting intravenous cotrimoxazole, and discontinuing the rest of the empirical treatment. A progressive improvement of the skin lesions followed. A cranial CT scan and chest X-ray were performed, ruling out systemic involvement. Finally, she was discharged with oral antibiotic therapy and follow-up visits. After 1 month of treatment, the patient continued with good clinical evolution (figure 5) with antibiotic therapy during 3 months.

Figure 4.

Microscope results.

Figure 5.

Improvement of lesions after antibiotic treatment.

Discussion

Nocardia is a Gram-positive aerobic acid-alcohol resistant bacterium member of the family Nocardiaceae, which belongs to a suborder of aerobic actinomycetes. They are opportunistic infectious agents, although one-third of infected patients are immunocompetent. Some of the risk factors related to the development of an infection are corticosteroids, a history of solid or haematological tumour, diabetes mellitus and chronic obstructive pulmonary disease. The most common organ manifestation is pulmonary nocardiosis. Subacute or chronic symptoms usually occur, including cough, expectoration, dyspnoea and haemoptysis, as well as weight loss, asthenia and sweating. Extrapulmonary involvement affects mainly at the central nervous system (CNS) or the skin.³

Cutaneous nocardiosis can be primary, in the case of inoculation by trauma with a plant or a tool contaminated by soil, or, mainly in immunosuppressed patients, a disseminated nocardiosis with secondary skin involvement.⁴ Primary skin nocardiosis is usually caused by N. brasiliensis.⁵ There are three forms of skin manifestation: superficial, lymphocutaneous and a chronic form mycetoma.⁶

Diagnosis is confirmed by the culture of clinical specimens from affected organs. Cultures usually take from 3 to 5 days. A Gram stain should also be performed, which is characteristic and shows more or less branched Gram-positive bacterial filaments (figure 4). Other stains such as Ziehl-Neelsen or modified Kinyoun can also be used. Nocardia can grow on conventional media such as blood agar and chocolate agar, as we used in this case. They also grow in specific media such as Löwenstein-Jensen or BCYE (Buffered Charcoal Yeast Extract). In our case, the cultures were incubated in a CO2 atmosphere at a temperature of 35°C–37°C. Colonies are wrinkled, creamy and produce a white pigment. The identification of the infectious agent is established by the characteristics of the culture in an aerobic medium, by the Gram stain. Finally, the definitive identification was carried out by mass spectrometry using Bruker’s MALDI-TF (Matrix-Assisted Laser Desorption/Ionization).⁵

The treatment is based on the combination of antimicrobials with adequate surgical drainage. Except for mild cases, it is recommended to start intravenous antibiotic therapy, usually with trimetopim-sulfamethoxazole in monotherapy. Linezolid is another option. In severe cases such as CNS involvement, combination therapy can be used by adding a third-generation cephalosporin or a carbapenem. Once the patient is stable and improves, antibiotics can be changed to oral therapy until a total duration of 6 months is completed. In cutaneous nocardiosis cases, this time can be reduced to 3 months.⁷

Learning points.

• Nodular lymphangitis has multiple microbiological aetiologies including sporotrichosis, nocardiosis and micobacteria.

• Cutaneous nocardiosis is less frequent than other clinical manifestations like pulmonary nocardiosis.

• The first choice of treatment is trimetroprim-sulfametoxazol.

Ethics statements

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