177: Helminthic Infections Flashcards
What are the hallmark features of cutaneous larva migrans caused by Ancylostoma braziliense?
Hallmark: creeping eruption
Characteristic lesion: erythematous, raised, and vesicular, linear or serpentine cutaneous trail that progresses at a rate of 2-3 cm per day.
Typically 1 to 3 serpiginous lesions, 3 mm wide and up to 20 cm in length.
Pruritus and urticaria after skin penetration and during larval migration.
Sites: feet and buttocks.
What are the clinical features associated with Ascaris lumbricoides?
Pruritus and urticaria during larval migration (with Loeffler syndrome).
Loeffler syndrome: hypersensitivity syndrome consisting of dyspnea, wheezing, cough; also seen with Strongyloides.
What is the primary treatment for Enterobius vermicularis (pinworm infection)?
Primary treatment: Albendazole 400 mg by mouth once.
Alternative treatments: Mebendazole 100 mg once; Pyrantel pamoate 11 mg/kg (max 1g) once.
What is the significance of Wolbachia bacteria in the treatment of filarial infections?
Wolbachia bacteria play a role in filarial development and host response for all filariasis except loiasis.
Doxycycline 100 to 200 mg by mouth daily for 6 to 8 weeks can reduce Wolbachia and block microfilariae production.
What are the common clinical features of Dirofilaria spp. infections?
Single erythematous, well-defined, firm nodule or mass, usually 1 to 5 cm in diameter; usually asymptomatic but may be tender.
Rarely may be migratory.
What is the most likely diagnosis for a patient with a creeping eruption on their foot characterized by a linear, serpentine cutaneous trail progressing at 2-3 cm per day, and what is the primary treatment?
The most likely diagnosis is Cutaneous Larva Migrans caused by Ancylostoma braziliense. The primary treatment is Albendazole 400 mg by mouth daily for 3 days.
What diagnostic method should be used for a patient with nocturnal anal pruritus suspected of having Enterobiasis, and what is the primary treatment?
The diagnostic method is the sticky-tape method. The primary treatment is Albendazole 400 mg by mouth once.
What is the causative organism for pruritic papular lesions at the site of larval entry, commonly referred to as ‘ground itch,’ and what is the treatment?
The causative organism is Ancylostoma duodenale or Necator americanus (human hookworm). Treatment includes Albendazole 400 mg by mouth daily for 3 days.
What is the likely causative organism for a patient presenting with a firm, erythematous nodule that is 1-5 cm in diameter and tender, and what is the typical presentation?
The likely causative organism is Dirofilaria spp. The typical presentation includes a single erythematous, well-defined, firm nodule or mass, usually asymptomatic but may be tender.
What is the diagnosis for a patient reporting a moving mass under their skin followed by the emergence of an adult worm, and what is the causative organism?
The diagnosis is Dracunculiasis, caused by Dracunculus medinensis.
What is the associated intestinal protozoan for a patient presenting with nocturnal pruritus ani and vulvovaginitis, and what symptoms might it produce?
The associated intestinal protozoan is Dientamoeba fragilis, which may produce gastrointestinal upset.
What diagnostic imaging sign is associated with tropical pulmonary eosinophilia and inguinal lymph node swelling?
The diagnostic imaging sign is the ‘filarial dance sign,’ observed in inguinal lymph node ultrasonography.
What is the recommended approach to minimize severe allergic reactions in a patient undergoing treatment for filariasis?
Start with a low dose of diethylcarbamazine (DEC) and escalate gradually to minimize allergic or febrile reactions.
What is the primary cause of Bancroftian filariasis and its main clinical features?
Bancroftian filariasis is primarily caused by Wuchereria bancrofti, which accounts for 90% of lymphatic filariasis cases. The main clinical features include:
- Hydrocele/scrotal mass caused by lymphatic obstruction
- Limb edema
- Extensive exfoliation of the skin of the affected limb.
What are the management options for Malayan filariasis caused by Brugia species?
Management options for Malayan filariasis, caused by Brugia malayi and Brugia timori, include:
- DEC 2 mg/kg by mouth thrice daily for 12 days
- In chronic cases, elevation of the affected limb, compression stockings, good skin care, and treatment of superficial fungal and bacterial infections are important.
- Surgical treatment can be considered in severe cases.
What is the characteristic symptom of Loiasis and how is it managed?
The characteristic symptom of Loiasis, caused by Loa Loa, is calabar swelling, which is localized angioedema due to the migration of adult worms through subcutaneous tissues. Management includes:
- DEC 3 mg/kg by mouth thrice daily for 21 days
- Surgical removal of the adult worm may be required in some cases.
What are the clinical features and treatment options for Mansonelliasis?
Mansonelliasis, caused by Mansonella perstans and Mansonella streptocerca, presents with:
- Early pruritus, which may be the only symptom
- Calabar-like swellings in the forearms, hands, and face
- Multiple pruritic papules, hypopigmented and hyperpigmented macules, and lichenification.
Treatment options include:
- For M. perstans: Doxycycline 100 to 200 mg daily for 6 to 8 weeks.
- For M. streptocerca: DEC 2 mg/kg by mouth thrice daily for 12 days or alternative Ivermectin 150 μg/kg by mouth once.
What are the key clinical features of Onchocerciasis and its management?
Onchocerciasis, caused by Onchocerca volvulus, is characterized by:
- Pruritus as the most prominent and persistent symptom
- Acute symptoms include widespread small pruritic papules, vesicles, and pustules on the face, extremities, and trunk.
- Chronic symptoms include intensely pruritic flat papules or macules on the buttocks, shoulders, and waist, and well-defined painless nodules containing adult worms.
Management includes:
- Ivermectin 150 μg/kg by mouth once, then every 6 months until asymptomatic.
- DEC should not be used due to the risk of ocular side effects from rapid killing of worms.
What is the most likely diagnosis for a patient presenting with hydrocele and limb edema, with blood tests revealing microfilariae, and what is the primary treatment?
The most likely diagnosis is Bancroftian Filariasis caused by Wuchereria bancrofti. The primary treatment is DEC 2 mg/kg by mouth thrice daily for 12 days.
What is the diagnosis for a patient presenting with localized angioedema around the joints of the upper extremities lasting 2-4 days, and what is the causative organism?
The diagnosis is Loiasis, caused by Loa Loa.
What is the diagnosis for a patient presenting with pruritic papules and hypopigmented macules on the forearms and face, and what is the treatment?
The diagnosis is Mansonelliasis caused by Mansonella perstans. The treatment is Doxycycline 100 to 200 mg daily for 6 to 8 weeks.
What is the diagnosis for a patient presenting with intensely pruritic flat papules on the buttocks and shoulders, along with well-defined, fixed nodules over bony prominences, and what is the primary treatment?
The diagnosis is Onchocerciasis (River Blindness) caused by Onchocerca volvulus. The primary treatment is Ivermectin 150 μg/kg by mouth once, then every 6 months until asymptomatic.
What is the diagnosis for a patient presenting with localized angioedema and migration of adult worms across the conjunctiva, and what surgical intervention might be required?
The diagnosis is Loiasis caused by Loa Loa. Surgical removal of the adult worm may be required.
What is the alternative treatment for Mansonella streptocerca for a patient presenting with pruritic papules and lichenification on the forearms and face?
The alternative treatment is Ivermectin 150 μg/kg by mouth once.
What is the diagnosis for a patient presenting with intensely pruritic, erythematous swelling of a limb, known as ‘Gros bras camerounais,’ and what is the causative organism?
The diagnosis is Onchocerciasis (River Blindness) caused by Onchocerca volvulus.
What are the clinical features of Gnathostoma spinigerum infections?
- Migration of larvae can cause creeping eruption
- Movement of larvae is approximately 1 cm per hour
- Intermittent single or multiple erythematous swellings; may be migratory, pruritic or painful; lasts 1 to 4 weeks with recurrences in different anatomical areas after variable asymptomatic periods
- Pruritus and urticaria during larval migration
- Eyelid edema.
What is the primary treatment for Strongyloides stercoralis infection?
- Ivermectin 200 μg/kg/day for 2 days is the primary treatment.
- An alternative treatment is Albendazole 400 mg by mouth twice daily for 7 days.
- In immunocompromised patients or in cases of disseminated disease, it may be necessary to prolong or repeat therapy.
- Combination therapy (ivermectin plus albendazole) may be indicated in disseminated disease.
What are the notable clinical features of Trichinella spiralis infections?
- Pruritus and urticaria during larval migration
- Violaceous periorbital edema
- Petechiae.
What are the clinical features associated with Fasciola hepatica infections?
- Erythematous, painful, pruritic subcutaneous nodules may have a migratory component; larval track marks may also be seen.
- Urticaria during migration of adult flukes.
What are the clinical features of Paragonimus westermani infections?
- Firm migratory swellings or nodules, may be migratory; slightly tender and slightly mobile, up to 6 cm in diameter; swellings contain immature flukes.
- Urticaria during larval migration.
What is the diagnosis for a patient presenting with intermittent erythematous swellings that are migratory and pruritic, lasting 1-4 weeks, and what is the causative organism?
The diagnosis is Cutaneous Larva Migrans caused by Gnathostoma spinigerum.
What is the diagnosis for a patient presenting with a migratory serpiginous lesion that moves at a rate of 5-10 cm per hour, and what is the pathognomonic sign of chronic infection?
The diagnosis is Strongyloidiasis caused by Strongyloides stercoralis. The pathognomonic sign of chronic infection is perianal larva currens.
What is the diagnosis for a patient presenting with violaceous periorbital edema and petechiae, and what is the causative organism?
The diagnosis is Trichinosis caused by Trichinella spiralis.
What is the diagnosis for a patient presenting with firm, migratory subcutaneous nodules up to 6 cm in diameter, and what is the causative organism?
The diagnosis is Paragonimiasis caused by Paragonimus westermani.
What is the diagnosis for a patient presenting with a unique pattern of periumbilical purpura resembling multiple thumbprints, and what is the causative organism?
The diagnosis is Strongyloidiasis caused by Strongyloides stercoralis.
What is the diagnosis for a patient presenting with a migratory, pruritic lesion that moves at a rate of 1 cm per hour, and what is the causative organism?
The diagnosis is Cutaneous Larva Migrans caused by Gnathostoma spinigerum.
What is the primary treatment for a patient presenting with perianal larva currens and Loeffler syndrome?
The primary treatment is Ivermectin 200 μg/kg/day for 2 days.
What is the diagnosis for a patient presenting with erythematous, painful subcutaneous nodules with larval track marks, and what is the causative organism?
The diagnosis is Fascioliasis caused by Fasciola hepatica.
What infections are commonly associated with pruritus and urticaria during larval migration?
Infections commonly associated with pruritus and urticaria during larval migration include Ascariasis, Strongyloidiasis, and Toxocariasis.
What are the notable diseases associated with Schistosoma spp. and their clinical features?
Notable diseases include Schistosomiasis/Bilharziasis. Clinical features are:
- Acute: Transient urticaria with pruritus within 24 hours of exposure, erythematous papular and urticarial lesions, onset within hours of freshwater exposure, urticaria with Katayama fever.
- Chronic: Slightly pigmented, firm, pruritic papules or papulonodular lesions, painless skin-colored or brown lesions, granulomatous hepatitis, and hepatic fibrosis.
What is the management for Schistosomiasis caused by Schistosoma haematobium, Schistosoma intercalatum, and Schistosoma mansoni?
Management includes:
1. Primary Treatment: Praziquantel 40 mg/kg/day in 1 or 2 doses for 1 day.
2. Alternative Treatment: Oxamniquine 15 mg/kg by mouth once (only for S. mansoni).
- Note: Oxamniquine is generally less effective than praziquantel but may be effective in some areas.
- In East Africa, increase oxamniquine dose to 30 mg/kg.
- In Egypt and South Africa, increase oxamniquine dose to 30 mg/kg/day for 2 days.
- Oxamniquine is contraindicated in pregnancy.
What are the clinical features of Echinococcus granulosis and Echinococcus multilocularis?
Clinical features include:
- Echinococcus granulosis: Firm subcutaneous or muscular nodules or masses, usually single but may be multiple; may feel fluctuant, nontender, rarely with fistulization and inflammation.
- Echinococcus multilocularis: True cutaneous.
What is the recommended oxamniquine dose in Egypt and South Africa?
Increase oxamniquine dose to 30 mg/kg/day for 2 days.
Is oxamniquine contraindicated in pregnancy?
Yes, oxamniquine is contraindicated in pregnancy.
What are the clinical features of Echinococcus granulosis?
Firm subcutaneous or muscular nodules or masses, usually single but may be multiple; may feel fluctuant, nontender, rarely with fistulization and inflammation.
What are the clinical features of Echinococcus multilocularis?
True cutaneous lesions are rare.
What is the significance of eosinophilia in helminthic infections?
Eosinophilia indicates an absolute eosinophil count of >500 eosinophils per mm³ and is associated with tissue invasion.
What may occur approximately 10 days after starting effective antihelminthic treatment?
Transient hypereosinophilia may occur.
How long may eosinophilia persist after successful helminth eradication?
Eosinophilia may persist for 1-2 months.
What infections are suggested by severe eosinophilia (>3000/mm³)?
Infections such as Ascariasis, Fascioliasis, Filariasis, and others.
What is the diagnosis for a patient with transient urticaria and pruritus after freshwater exposure?
The diagnosis is Schistosomiasis (Acute phase) caused by Schistosoma spp.
What is the diagnosis and treatment for slightly pigmented, firm, pruritic papules?
The diagnosis is Chronic Schistosomiasis (Bilharziasis cutanea tarda). The treatment is Praziquantel 40 mg/kg/day in 1 or 2 doses.
What is the diagnosis for firm subcutaneous nodules that are painless?
The diagnosis is Cysticercosis caused by Taenia solium.
What is the diagnosis for slow-growing, painful swellings that are migratory?
The diagnosis is Sparganosis caused by Spirometra mansonoides.
What is the key factor in the development of eosinophilia?
Tissue invasion is the key factor.
What is the diagnosis for a patient with granulomatous hepatitis and hepatic fibrosis?
The diagnosis is Chronic Schistosomiasis caused by Schistosoma spp.
What is the primary treatment for firm, slightly tender, migratory nodules?
The primary treatment is Praziquantel 60 mg/kg/day in 2 or 3 doses for 1 day.
What is the primary treatment for Schistosoma japonicum?
The primary treatment is Praziquantel 60 mg/kg/day in 2 or 3 doses for 1 day.
What is the diagnosis for painless, fixed, rubbery subcutaneous nodules?
The diagnosis is Cysticercosis caused by Taenia solium.
What is the diagnosis for slow-growing, migratory, painful swellings?
The diagnosis is Sparganosis caused by Spirometra mansonoides.
What is the expected duration of eosinophilia after successful treatment?
Eosinophilia may persist for one to two months after successful helminth eradication.
What is the primary treatment for Schistosoma mansoni?
The primary treatment is Praziquantel 40 mg/kg/day in 1 or 2 doses for 1 day.
What is the diagnosis for a firm subcutaneous nodule that is fluctuant and nontender?
The diagnosis is Echinococcosis caused by Echinococcus granulosus.
What is the diagnosis for a solitary, painless subcutaneous nodule 2-6 cm in diameter?
The diagnosis is Coenurosis caused by Taenia multiceps.
What is the likely explanation for transient hypereosinophilia after starting antihelminthic treatment?
Transient hypereosinophilia is a common response to effective antihelminthic treatment.
What is the diagnostic hallmark of Cysticercosis?
The diagnostic hallmark is the presence of painless, fixed, rubbery subcutaneous nodules.
