Dermatology Online Journal

Cutaneous manifestation of disseminated strongyloidiasis in a patient coinfected with HTLV-I
Emily L Arch MD¹, Jochen T Schaefer MD², Anjali Dahiya MD PhD¹
Dermatology Online Journal 14 (12): 6

1. Department of Dermatology
2. Department of Pathology and Laboratory Medicine, Dermatopathology Division
Weill Medical College of Cornell University, New York, New York. eml2002@nyp.org

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Abstract

Strongyloidiasis is a potentially lethal parasitic infection. Coinfection of a patient with human T-lymphotropic virus type I (HTLV-I) can lead to a more severe disease course and treatment-refractoriness. Here we report a patient coinfected with HTLV-I and Strongyloides stercoralis who developed disseminated, treatment-resistant disease. The patient presented with serpiginous, nonpalpable, purpuric streaks on the abdomen and proximal lower extremities. A biopsy of this eruption demonstrating filariform larvae in the dermis was consistent with disseminated strongyloidiasis. The patient's immune dysregulation due to HTLV-I positivity likely contributed to her development of disseminated disease. Awareness of the interaction between HTLV-I and strongyloidiasis has important implications in terms of prognosis and treatment. Recognition of the cutaneous manifestations of disseminated disease can facilitate diagnosis and implementation of appropriate therapy.

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Introduction

Strongyloides stercoralis is a parasitic nematode endemic to tropical and subtropical regions. Coinfection of patients with HTLV-I can lead to a more severe course and treatment-refractoriness. We describe a patient coinfected with HTLV-I and S. stercoralis who developed disseminated disease.

Case report

A 43-year-old woman who emigrated to the United States from Ghana eight years ago was admitted to our institution complaining of abdominal pain, nausea, diarrhea, and anal itching of several days duration. Her medical history was remarkable for multiple Strongyloides stercoralis infections in recent years that had been treated with oral ivermectin and albendazole. The most recent episode occurred two months prior to admission. On admission to our hospital she was treated with empiric oral ivermectin (12 mg PO qday) and albendazole (400 mg PO per day). Stool studies later confirmed the presence of Strongyloides larvae. Initial laboratory evaluation was significant for white blood cell count of 12.2 K/uL with eosinophilia of 7.6 percent, HIV negativity, and HTLV-I and -II positivity.

The patient's hospital course was complicated by development of acute respiratory distress and fever requiring transfer to the medical intensive care unit. A bronchoalveolar lavage (BAL) was positive for S. stercoralis larvae. The patient developed a small bowel obstruction that may have impaired absorption of the ivermectin. Because of this, she was started on per rectum (PR) ivermectin (6mg PR q12) in addition to per nasogastric tube (NGT) ivermectin and albendazole. At this time the patient was noted to have a new cutaneous eruption and the dermatology service was consulted.

Figure 1	Figure 2
Figure 1. Right proximal thigh with serpiginous nonpalpable purpuric streaks Figure 2. Filariform larva in the dermis (H&E, x100)

On examination the patient had serpiginous and linear purpuric, nonpalpable erythematous streaks on the abdomen and anterior and lateral thighs (Fig. 1). A punch biopsy was obtained from an abdominal lesion. Pathology revealed scattered filariform larvae compatible with S. stercoralis larvae as well as a modest lymphocytic infiltrate within the superficial dermis and tissue eosinophilia (Fig. 2). After several days of per NGT and PR ivermectin the patient's stools and repeat BAL became negative for Strongyloides. She was extubated and her condition gradually improved. Her cutaneous eruption resolved completely.

Discussion

Strongyloidiasis is caused by the soil-dwelling nematode Strongyloides stercoralis. This parasite is endemic to tropical and subtropical regions throughout the world including areas of the southeastern United States and Appalachia and affects 100 million people worldwide [1]. Humans are infected transcutaneously by filariform larvae that subsequently travel via the venous system to the lungs. There they eventually enter the pharynx and are swallowed. In the small intestine adult female worms produce eggs that hatch rhabditiform larvae. These larvae pass in the stool to continue the free-living external life cycle or develop into filariform larvae that can reinfect the host by penetration of the perianal skin or intestinal wall [2]. This latter process is termed "autoinfection" and can occur at low levels throughout the course of infection [2].

Strongyloidiasis has a wide range of manifestations from asymptomatic disease to disseminated infection. Acute and chronic infection, hyperinfection syndrome, and disseminated infection are described [2]. Cutaneous manifestations of acute strongyloidiasis are not well characterized, but local urticarial reaction at the site of larval entry may occur [3]. Pulmonary and gastrointestinal symptoms have been described, with larvae detectable in stool within three to four weeks [2]. Chronic infection is most frequently asymptomatic [4]. Dermatological manifestations include chronic urticarial lesions of the buttocks and waistline that last one to two days [5]. Larva currens is pathognomonic of chronic Strongyloides infection and is caused by filiariform larval migration in the skin [6, 7]. This manifests as intensely pruritic serpiginous urticarial wheals that move at a rate of 5-15 cm/hour and occur mainly on the buttocks, groin, and trunk. Biopsies have not revealed larvae [5]. Hyperinfection occurs with accelerated autoinfection, usually as a result of immunosuppression that leads to increased multiplication and migration of larvae [2]. This increased larval burden produces exacerbated gastrointestinal and pulmonary symptoms. When larvae migrate beyond the pulmonary and intestinal systems, the term "disseminated infection" is used. Cutaneous manifestations of disseminated disease, as seen in our patient, include progressive petechial and purpuric eruptions on the abdomen and proximal extremities. As we have shown, larvae can be demonstrated on routine hematoxylin-eosin stains [5, 8]. The larvae migrate through blood vessel walls into the dermis causing hemorrhage and the petechial appearance of this eruption [8].

The patient described was coinfected with HTLV-I and II. Infection with HTLV-I is associated with more severe and treatment-refractory strongyloidiasis and it has been suggested that Strongyloides infection shortens the latency period to leukemogenesis in those infected with HTLV-I [2]. Coinfected patients frequently lack eosinophilia and anti-strongyloides IgE due to an antagonistic immune systemic response to each infection [2]. In our patient, this coinfection likely contributed to the treatment-refractory nature of her infection and eventual disseminated disease. In immunocompromised patients or those coinfected with HTLV-I and Strongyloides, combination therapy with albendazole and ivermectin should be considered. Treatment is continued until there is evidence of eradication of infection (resolution of eosinophilia or negative stool studies for at least two weeks) [2, 9].

We describe a patient coinfected with HTLV-I and II and Strongyloides stercoralis who developed disseminated disease. Coinfection with HTLV-I has only recently been described as leading to more severe and treatment-refractory Strongyloides infection [2]. The cutaneous findings of serpiginous purpuric streaks on the abdomen and proximal lower extremities that demonstrated larvae upon biopsy helped to diagnose disseminated strongyloidiasis. This is a potentially lethal parasitic infection and clinicians should consider the diagnosis in patients with gastrointestinal, pulmonary, and cutaneous signs and symptoms, particularly in those who are immunocompromised and who originate from endemic areas.

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