J AM ACAD DERMATOL VOLUME 70, NUMBER 5
JAAD grand rounds 961
performed until 4 weeks after infection because seroconversion is often delayed. For this series, the recommended choices are: 5, e; 6, b; 7, a; 8, b.
11. What is the causative organism? a. Strongyloides stercoralis b. Ascariasis lumbricoides c. Enterobius vermicularis d. Ancylostoma canium or A braziliense
BIBLIOGRAPHY Althaus F, Greub G, Raoult D, Genton B. African tick-bite fever: a new entity in the differential diagnosis of multiple eschars in travelers. Description of five cases imported from South Africa to Switzerland. Int J Infect Dis 2010;14(suppl 3):e274-6. Jackson Y, Chappuis F, Loutan L. African tick-bite fever: four cases among Swiss travelers returning from South Africa. J Travel Med 2004;11:225-8. Jensenius M, Fournier PE, Fladby T, Hellum KB, Hagen T, Priø T, et al. Sub-acute neuropathy in patients with African tick bite fever. Scand J Infect Dis 2006;38:114-8. Jensenius M, Fournier PE, Kelly P, Myrvang B, Raoult D. African tick bite fever. Lancet Infect Dis 2003;3:557-64. McQuiston JH, Paddock CD, Singleton J, Wheeling JT, Zaki SR, Childs JE. Imported spotted fever rickettsioses in United States travelers returning from Africa: a summary of cases confirmed by laboratory testing at the Centers for Disease Control and Prevention, 1999-2002. Am J Trop Med Hyg 2004;70:98-101. Raoult D, Fournier PE, Fenollar F, Jensenius M, Prioe T, de Pina JJ, et al. Rickettsia africae, a tick-borne pathogen in travelers to sub-Saharan Africa. N Engl J Med 2001;344:1504-10. Roch N, Epaulard O, Pelloux I, Pavese P, Brion JP, Raoult D, et al. African tick bite fever in elderly patients: 8 cases in French tourists returning from South Africa. Clin Infect Dis 2008;47: e28-35.
Discussion Cutaneous larva migrans is caused by the larvae of the dog or cat hookworm, most commonly Ancylostoma brazilliense or A caninum. The hookworm is endemic to warmer, tropical, and subtropical climates, especially the central and southeastern United States, Southeast Asia, Africa, South America, and the Caribbean. Cutaneous larva migrans is usually acquired by walking barefoot on ground that has been contaminated with feces, but any exposed area can be affected if it comes into contact with soil or sand that has been infected. Once the larvae enter the skin, they migrate within the epidermis. Except in rare instances, the parasite is confined to the epidermis because it lacks the collagenase necessary to break through the basement membrane. Clinically, symptoms will appear 1 to 6 days after infection, most frequently on the lower extremities, and begin as a pruritic, erythematous papule at the site of penetration. The ‘‘creeping eruption’’ can also occur on the buttocks and hands. Because hosts may be in heavily contaminated soil, it is possible to become infected with multiple larvae and therefore have multiple penetration sites. After initial penetration, the larvae migrate, creating tunnel-like, erythematous, serpiginous palpable lesions that are extremely pruritic. The linear lesions are usually 2 to 3 mm in width, elongating as the larvae travels, often developing a vesicular appearance as serous fluid accumulates. The larvae travel 1 to 2 cm per day. Complications of infection include crusting, ulceration, and secondary infection. The diagnosis is often clinical and is based on a patient’s history and clinical findings. Biopsy specimens of the advancing part of the lesion may reveal the parasite with eosinophilic infiltrate. The differential should include other migrating nematodes, including Strongyloides, which migrates more rapidly than A brazilliense (1 cm/hour as opposed to 1 cm/day). Infection can be prevented by minimizing direct skin contact with contaminated soil. When patients are travelling to endemic areas, they should be advised to wear close-toed shoes, socks, and longer pants. Ultimately, the lesions will resolve spontaneously in 2 to 8 weeks; however, it is important to treat to prevent secondary complications and minimize the intense pruritis. Extraction should not be attempted, and the best treatment for adults is oral
Vacation dermatoses Jessica Connett, MD, and Rosalyn George, MD Charleston, South Carolina, and Wilmington, North Carolina CASE 1 A 6-year-old boy presented with an intensely pruritic rash on his left lower extremity after vacationing in Costa Rica (Fig 9). He was seen in a local urgent care center, and over the course of 2 weeks was treated with multiple antibiotic ointments and oral antibiotics with no improvement. His mother reported that the patient frequented the beach while in Costa Rica, and that there were often stray dogs on the beach. 9. Which of the following is the correct diagnosis? a. Strongyloidiasis b. Cutaneous larvae migrans c. Allergic contact dermatitis d. Jellyfish sting 10. What is the best treatment for this condition? a. Oral ivermectin b. Hydroxyzine c. Hydrocortisone d. Oral albendazole
962 JAAD grand rounds
J AM ACAD DERMATOL
MAY 2014
ivermectin 200 mcg/kg orally once daily for 1 to 2 days and 150 mcg/kg once for pediatric dosing. Symptoms should subside within a week of treatment. Other treatment options include oral albendazole or topical or oral thiabendazole. CASE 2 A 26-year-old white man presented to our clinic after returning from a mission trip in Africa. While on his trip, he spent a lot of time playing soccer, and recalls frequently playing without wearing shoes. Upon returning home, he developed slightly tender papules on the sole of his right foot (Fig 10). 12. What is the causative organism? a. Tunga penetrans b. Botfly c. Sarcoptes scabiei d. Strongyloides species 13. What is the best treatment for this condition? a. Ivermectin b. Surgical excision c. Permethrin d. Petrolatum occlusion Discussion Tungiasis is an infection caused by the female sand flea Tunga penetrans, an arthropod endemic to Central and South America, the Caribbean, and subSaharan Africa. The parasite, approximately 1 mm in size, lives in dry and sandy soil, and causes infection by penetrating the epidermis of its host, feeding on blood, producing eggs, and expelling eggs back into the environment. The flea usually penetrates the feet, but cases have been reported of ectopic infections, such as hands, elbows, and the anogenital region. Tungiasis is more common in developing countries where people often go without shoes, and the prevalence has been reported to be as high as 40% in certain areas. The life cycle of the flea within the host is divided into distinct stages, each differing in clinical signs, symptoms, and histopathology (Fig 11). The entire
process from penetration to parasite death lasts for 4 to 6 weeks; however, residues can persist for several months, leaving an erythematous, desquamated lesion. The flea penetrates the epidermis during the first stage, leaving only the posterior abdominal segment protruding through the skin. Clinical symptoms are rare, although patients may feel a bite with entry followed by a pruritic, erythematous papule at the entrance site. If a biopsy specimen is obtained, the site may show epidermal hyperplasia, hyperkeratosis, and parakeratosis, with minimal inflammatory infiltrate in the dermis surrounding the parasite. Symptoms including increasing erythema, itching, and pain are more commonly experienced by the host during the second stage, when the epidermis begins to hypertrophy around the flea. There is an increase in inflammatory infiltrate in both the epidermis and the dermis, with an increasing perivascular infiltrate of mainly neutrophils, lymphocytes, and eosinophils. During the third stage, the flea’s abdomen swells and enlarges to 5 to 8 mm, causing the papule to have a white halo surrounding a small, central black dot where the flea excretes eggs and feces, producing brown secretions and infiltrate in the papillae of the surrounding skin. The lesion
J AM ACAD DERMATOL VOLUME 70, NUMBER 5
continues to grow, becoming more edematous and painful, with a pulsation sensation felt secondary to the release of feces and eggs. Symptoms are often worse at night and when touched. Approximately 150 to 200 eggs are expelled for about a week. In the epidermis and the dermis, one may see clusters of bacteria and microabscesses with increasing blood vessel dilation and increased inflammatory infiltrate. Later in the third stage, desquamation frequently occurs with shrinking of the papule. Stage four occurs after all eggs are released; the female flea dies and the lesion involutes, appearing discolored and wrinkled. Bacteria and neutrophils surround the parasite and then fill the parasite confirming that the parasite expires during this stage. Once the parasite is eliminated, the lesion becomes a brown-black crust with mild itching experienced by the host. Diagnosis is often clinical in endemic areas, although a biopsy specimen can give a more definitive diagnosis and is more commonly performed when infected travelers return home. Complications from tungiasis include secondary infections from staphylococcal, streptococcal, and Enterobacteriaceae species. Tetanus can occur, especially in endemic areas where vaccination coverage is minimal. The standard of care is to remove the flea, although therapy options include both surgical and medical treatment. The flea and any remnants should be
JAAD grand rounds 963
surgically removed with sterile instruments or using cryotherapy and electrodessication. Medical options include petroleum jelly to suffocate the flea, oral thiabendazole (25 mg/kg/day) or albendazole (400 mg/day for 3 days) for infestations, topical ivermectin, or metrifonate. Any signs of secondary infection should be treated with topical or oral antibiotic treatments covering both staphylococcal and streptococcal species. If traveling to an endemic area, close-toed shoes can prevent infection, while checking for signs of infection can allow immediate removal of the flea, preventing worsening infection and complications. For this series, the recommended choices are: 9, b; 10, a; 11, d; 12, a; 13, b.
BIBLIOGRAPHY Eisele M, Heukelbach J, Van Marck E, Mehlhorn H, Meckes O, Franck S, et al. Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: natural history of tungiasis in man. Parasitol Res 2003;90:87-99. Heukelbach J, Sales de Oliveira FA, Hesse G, Feldmeier H. Tungiasis: a neglected health problem of poor communities. Trop Med Int Health 2001;6:267-72. Weller P, Leder K. Cutaneous larva migrans (creeping eruption). In: Ryan ET, editor. Waltham (MA): UpToDate; 2012. Wolff K, Johnson RA, Suurmond D. Fitzpatrick’s color atlas and synopsis of clinical dermatology . 5th ed. New York: McGraw-Hill; 2005.
JAAD grand rounds 961
performed until 4 weeks after infection because seroconversion is often delayed. For this series, the recommended choices are: 5, e; 6, b; 7, a; 8, b.
11. What is the causative organism? a. Strongyloides stercoralis b. Ascariasis lumbricoides c. Enterobius vermicularis d. Ancylostoma canium or A braziliense
BIBLIOGRAPHY Althaus F, Greub G, Raoult D, Genton B. African tick-bite fever: a new entity in the differential diagnosis of multiple eschars in travelers. Description of five cases imported from South Africa to Switzerland. Int J Infect Dis 2010;14(suppl 3):e274-6. Jackson Y, Chappuis F, Loutan L. African tick-bite fever: four cases among Swiss travelers returning from South Africa. J Travel Med 2004;11:225-8. Jensenius M, Fournier PE, Fladby T, Hellum KB, Hagen T, Priø T, et al. Sub-acute neuropathy in patients with African tick bite fever. Scand J Infect Dis 2006;38:114-8. Jensenius M, Fournier PE, Kelly P, Myrvang B, Raoult D. African tick bite fever. Lancet Infect Dis 2003;3:557-64. McQuiston JH, Paddock CD, Singleton J, Wheeling JT, Zaki SR, Childs JE. Imported spotted fever rickettsioses in United States travelers returning from Africa: a summary of cases confirmed by laboratory testing at the Centers for Disease Control and Prevention, 1999-2002. Am J Trop Med Hyg 2004;70:98-101. Raoult D, Fournier PE, Fenollar F, Jensenius M, Prioe T, de Pina JJ, et al. Rickettsia africae, a tick-borne pathogen in travelers to sub-Saharan Africa. N Engl J Med 2001;344:1504-10. Roch N, Epaulard O, Pelloux I, Pavese P, Brion JP, Raoult D, et al. African tick bite fever in elderly patients: 8 cases in French tourists returning from South Africa. Clin Infect Dis 2008;47: e28-35.
Discussion Cutaneous larva migrans is caused by the larvae of the dog or cat hookworm, most commonly Ancylostoma brazilliense or A caninum. The hookworm is endemic to warmer, tropical, and subtropical climates, especially the central and southeastern United States, Southeast Asia, Africa, South America, and the Caribbean. Cutaneous larva migrans is usually acquired by walking barefoot on ground that has been contaminated with feces, but any exposed area can be affected if it comes into contact with soil or sand that has been infected. Once the larvae enter the skin, they migrate within the epidermis. Except in rare instances, the parasite is confined to the epidermis because it lacks the collagenase necessary to break through the basement membrane. Clinically, symptoms will appear 1 to 6 days after infection, most frequently on the lower extremities, and begin as a pruritic, erythematous papule at the site of penetration. The ‘‘creeping eruption’’ can also occur on the buttocks and hands. Because hosts may be in heavily contaminated soil, it is possible to become infected with multiple larvae and therefore have multiple penetration sites. After initial penetration, the larvae migrate, creating tunnel-like, erythematous, serpiginous palpable lesions that are extremely pruritic. The linear lesions are usually 2 to 3 mm in width, elongating as the larvae travels, often developing a vesicular appearance as serous fluid accumulates. The larvae travel 1 to 2 cm per day. Complications of infection include crusting, ulceration, and secondary infection. The diagnosis is often clinical and is based on a patient’s history and clinical findings. Biopsy specimens of the advancing part of the lesion may reveal the parasite with eosinophilic infiltrate. The differential should include other migrating nematodes, including Strongyloides, which migrates more rapidly than A brazilliense (1 cm/hour as opposed to 1 cm/day). Infection can be prevented by minimizing direct skin contact with contaminated soil. When patients are travelling to endemic areas, they should be advised to wear close-toed shoes, socks, and longer pants. Ultimately, the lesions will resolve spontaneously in 2 to 8 weeks; however, it is important to treat to prevent secondary complications and minimize the intense pruritis. Extraction should not be attempted, and the best treatment for adults is oral
Vacation dermatoses Jessica Connett, MD, and Rosalyn George, MD Charleston, South Carolina, and Wilmington, North Carolina CASE 1 A 6-year-old boy presented with an intensely pruritic rash on his left lower extremity after vacationing in Costa Rica (Fig 9). He was seen in a local urgent care center, and over the course of 2 weeks was treated with multiple antibiotic ointments and oral antibiotics with no improvement. His mother reported that the patient frequented the beach while in Costa Rica, and that there were often stray dogs on the beach. 9. Which of the following is the correct diagnosis? a. Strongyloidiasis b. Cutaneous larvae migrans c. Allergic contact dermatitis d. Jellyfish sting 10. What is the best treatment for this condition? a. Oral ivermectin b. Hydroxyzine c. Hydrocortisone d. Oral albendazole
962 JAAD grand rounds
J AM ACAD DERMATOL
MAY 2014
ivermectin 200 mcg/kg orally once daily for 1 to 2 days and 150 mcg/kg once for pediatric dosing. Symptoms should subside within a week of treatment. Other treatment options include oral albendazole or topical or oral thiabendazole. CASE 2 A 26-year-old white man presented to our clinic after returning from a mission trip in Africa. While on his trip, he spent a lot of time playing soccer, and recalls frequently playing without wearing shoes. Upon returning home, he developed slightly tender papules on the sole of his right foot (Fig 10). 12. What is the causative organism? a. Tunga penetrans b. Botfly c. Sarcoptes scabiei d. Strongyloides species 13. What is the best treatment for this condition? a. Ivermectin b. Surgical excision c. Permethrin d. Petrolatum occlusion Discussion Tungiasis is an infection caused by the female sand flea Tunga penetrans, an arthropod endemic to Central and South America, the Caribbean, and subSaharan Africa. The parasite, approximately 1 mm in size, lives in dry and sandy soil, and causes infection by penetrating the epidermis of its host, feeding on blood, producing eggs, and expelling eggs back into the environment. The flea usually penetrates the feet, but cases have been reported of ectopic infections, such as hands, elbows, and the anogenital region. Tungiasis is more common in developing countries where people often go without shoes, and the prevalence has been reported to be as high as 40% in certain areas. The life cycle of the flea within the host is divided into distinct stages, each differing in clinical signs, symptoms, and histopathology (Fig 11). The entire
process from penetration to parasite death lasts for 4 to 6 weeks; however, residues can persist for several months, leaving an erythematous, desquamated lesion. The flea penetrates the epidermis during the first stage, leaving only the posterior abdominal segment protruding through the skin. Clinical symptoms are rare, although patients may feel a bite with entry followed by a pruritic, erythematous papule at the entrance site. If a biopsy specimen is obtained, the site may show epidermal hyperplasia, hyperkeratosis, and parakeratosis, with minimal inflammatory infiltrate in the dermis surrounding the parasite. Symptoms including increasing erythema, itching, and pain are more commonly experienced by the host during the second stage, when the epidermis begins to hypertrophy around the flea. There is an increase in inflammatory infiltrate in both the epidermis and the dermis, with an increasing perivascular infiltrate of mainly neutrophils, lymphocytes, and eosinophils. During the third stage, the flea’s abdomen swells and enlarges to 5 to 8 mm, causing the papule to have a white halo surrounding a small, central black dot where the flea excretes eggs and feces, producing brown secretions and infiltrate in the papillae of the surrounding skin. The lesion
J AM ACAD DERMATOL VOLUME 70, NUMBER 5
continues to grow, becoming more edematous and painful, with a pulsation sensation felt secondary to the release of feces and eggs. Symptoms are often worse at night and when touched. Approximately 150 to 200 eggs are expelled for about a week. In the epidermis and the dermis, one may see clusters of bacteria and microabscesses with increasing blood vessel dilation and increased inflammatory infiltrate. Later in the third stage, desquamation frequently occurs with shrinking of the papule. Stage four occurs after all eggs are released; the female flea dies and the lesion involutes, appearing discolored and wrinkled. Bacteria and neutrophils surround the parasite and then fill the parasite confirming that the parasite expires during this stage. Once the parasite is eliminated, the lesion becomes a brown-black crust with mild itching experienced by the host. Diagnosis is often clinical in endemic areas, although a biopsy specimen can give a more definitive diagnosis and is more commonly performed when infected travelers return home. Complications from tungiasis include secondary infections from staphylococcal, streptococcal, and Enterobacteriaceae species. Tetanus can occur, especially in endemic areas where vaccination coverage is minimal. The standard of care is to remove the flea, although therapy options include both surgical and medical treatment. The flea and any remnants should be
JAAD grand rounds 963
surgically removed with sterile instruments or using cryotherapy and electrodessication. Medical options include petroleum jelly to suffocate the flea, oral thiabendazole (25 mg/kg/day) or albendazole (400 mg/day for 3 days) for infestations, topical ivermectin, or metrifonate. Any signs of secondary infection should be treated with topical or oral antibiotic treatments covering both staphylococcal and streptococcal species. If traveling to an endemic area, close-toed shoes can prevent infection, while checking for signs of infection can allow immediate removal of the flea, preventing worsening infection and complications. For this series, the recommended choices are: 9, b; 10, a; 11, d; 12, a; 13, b.
BIBLIOGRAPHY Eisele M, Heukelbach J, Van Marck E, Mehlhorn H, Meckes O, Franck S, et al. Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: natural history of tungiasis in man. Parasitol Res 2003;90:87-99. Heukelbach J, Sales de Oliveira FA, Hesse G, Feldmeier H. Tungiasis: a neglected health problem of poor communities. Trop Med Int Health 2001;6:267-72. Weller P, Leder K. Cutaneous larva migrans (creeping eruption). In: Ryan ET, editor. Waltham (MA): UpToDate; 2012. Wolff K, Johnson RA, Suurmond D. Fitzpatrick’s color atlas and synopsis of clinical dermatology . 5th ed. New York: McGraw-Hill; 2005.
