HELMINTH INFECTIONS & THEIR CUTANEOUS MANIFESTATIONS Brittany Grady, DO DISCLOSURES I have no conflicts of interest to declare LEARNING OBJECTIVES: • Describe the cutaneous manifestations of helminth infections • Recognize recent developments and incidence of helminth infections within the United States of America • Evaluate, diagnose, and treat affected patients more knowledgeably and effectively WHAT IS A HELMINTH? • Helminths (worms) are large, multicellular organisms • Often visible to the naked eye • Free-living or parasitic • Belong to 2 different phyla: • Roundworms (Nematodes) • Flatworms (Platyhelminthes) ROUNDWORMS (NEMATODES) • Unsegmented • Each species has 2 different sexes • Contain a body cavity and digestive tract FLATWORMS (PLATYHELMINTHES) • Segmented or unsegmented • Primarily hermaphroditic • Do not have a body cavity • Further subdivided into 2 different classes: • Flukes (Trematodes) • Tapeworms (Cestodes) ROUNDWORM (NEMATODE) INFECTIONS • Cutaneous Larva Migrans • Onchocerciasis • Filariasis • Strongyloidiasis • Trichinosis • Toxocariasis CUTANEOUS LARVA MIGRANS (CLM) • AKA Creeping Eruption • CLM primarily affects people in tropical and subtropical climates, including the SE United States • Caused by animal hookworms, most commonly Ancylostoma braziliense and A. caninum • Eggs are eliminated via animal (cat or dog) feces and larvae mature in the sand/soil • Larvae infiltrate exposed skin surfaces of humans (end hosts) • Confined to the epidermis (lack collagenase) CLM X X X CUTANEOUS LARVA MIGRANS (CLM) • Larval migration through the epidermis (1-2 cm/day) • Clinical features: • Localized, intense pruritus • Linear or serpiginous raised erythematous “tracts” • +/- vesiculation • Most frequent location is distal lower extremities or buttocks • Diagnosis usually made clinically (biopsy rarely helpful) W. Infectious Diseases of the Skin. In: McKee’s Pathology of the Skin 4th ed. Edinburgh: ElsevierGrayson/Saunders; 2012: 761-895 Nelson SA, Warschaw KE. Protozoa and Worms. In: Dermatology 3rd ed. Edinburgh: Elsevier/Saunders; 2012: 1391-1421 www.visualdx.com Grady BE, Baum B. A Classic Case of Cutaneous Larva Migrans. 2013. http://www.consultantlive.com/skin-diseases/content/article/10162/2148906 CUTANEOUS LARVA MIGRANS (CLM) • Self-limited, but patients typically seek medical treatment • Treatment options: • PO Albendazole 400-800mg/day (Peds: 10-15 mg/kg/day) x 3-5 days • PO Ivermectin 12mg (Peds: 150 mcg/kg) x 1 • Topical 10-15% thiabendazole solution or ointment TID x 15 days • Cryotherapy to leading edge of skin tract (often unreliable) ONCHOCERCIASIS • AKA River Blindness • Onchocerciasis primarily affects people in tropical Africa • Caused by Onchocerca volvulus • Transmitted via blood meal of infected black fly (Simulium spp.) • Larvae mature into adult worms in the dermis and subcutis • Mature adult female worms become encapsulated in fibrous tissue (onchocercomas) • Each worm produces hundreds of microfilariae which migrate to the skin, connective tissue, eyes, and lymph nodes Grayson W. Infectious Diseases of the Skin. In: McKee’s Pathology of the Skin 4th ed. Edinburgh: Elsevier/Saunders; 2012: 761-895 Grayson W. Infectious Diseases of the Skin. In: McKee’s Pathology of the Skin 4th ed. Edinburgh: Elsevier/Saunders; 2012: 761-895 www.who.int/intestinal_worms/en ONCHOCERCIASIS • Clinical features: • Onchocercomas- firm, freely mobile subQ nodules often located over bony prominences • Acute papular onchodermatitis chronic onchodermatitis lichenification, atrophy, depigmentation • “Hanging groin”- chronic lymphatic obstruction of inguinal lymph nodes • Progressive sclerosing keratitis can lead to blindness in severe cases • 2nd most common cause of infection-related blindness • Accounts for 0.8% of overall blindness globally www.visualdx.com Nelson SA, Warschaw KE. Protozoa and Worms. In: Dermatology 3rd ed. Edinburgh: Elsevier/Saunders; 2012: 1391-1421 www.visualdx.com Grayson W. Infectious Diseases of the Skin. In: McKee’s Pathology of Nelson SA, Warschaw KE. Protozoa and Worms. In: Dermatology the Skin 4th ed. Edinburgh: Elsevier/Saunders; 2012: 761-895 3rd ed. Edinburgh: Elsevier/Saunders; 2012: 1391-1421 Grayson W. Infectious Diseases of the Skin. In: McKee’s Pathology of the Skin 4th ed. Edinburgh: Elsevier/Saunders; 2012: 761-895 ONCHOCERCIASIS • Treatment options: • DOC: PO Ivermectin 150 mcg/kg x 1 q3-12 months • Treatment continued for worm’s lifetime (10-15 years) • Adjunct: PO Doxycycline 100-200mg/day x 6 weeks • Targets Wolbachia endobacteria that reside within the O. volvulus nematodes • Wolbachia is responsible for inflammation that leads to subsequent protective fibrosis • Nodulectomy: surgical removal of onchocercomas from head/neck reduces the incidence of ocular disease FILARIASIS • AKA Elephantiasis • Filariasis primarily affects individuals in tropical or subtropical regions, including the Caribbean Islands and South America • Caused by Wucheria bancrofti (90% of cases) • Transmitted via bite of infected mosquitoes • Deposited larvae migrate to lymphatic system and develop into adult worms • Adult worms release microfilariae into the bloodstream Cano J, Rebollo MP, Golding N, et al. The Global Distribution and Transmission Limits of Lymphatic Filariasis: Past and Present. Parasites & Vectors. 2014 Oct; 7: 466 www.visualdx.com FILARIASIS • After 10-15 years of infection, the clinical features of chronic disease become evident • Leading cause of permanent disability worldwide • Clinical features: • Acute adenolymphangitis associated with fevers and chills (recurrent) • Chronic lymphedema hypertrophy of skin (hyperkeratotic, verrucous, fibrotic) redundant folds deformity • Secondary bacterial and fungal infections common • Most commonly affected sites: lower extremities and genitalia www.visualdx.com www.visualdx.com James WD, Berger TG, Elston DM. Parasitic Infestations, Stings, and Bites. In: Andrews’ Diseases of the Skin: Clinical Dermatology 11th ed. Edinburgh: Elsevier/Saunders; 2011: 414-447 FILARIASIS • Treatment options: • DOC: PO Diethylcarbamazine 6 mg/kg/day x 12 days • Active against microfilariae, limited effect on adult worms • Adult worm lifespan in host approx. 5-10 years • Adjunct: PO Doxycycline 200mg/day x 4-8 weeks • Targets Wolbachia endobacteria • Supportive care: limb elevation, compression stockings, protection from trauma, NSAIDs STRONGLYLOIDIASIS • AKA Larva Currens • Worldwide distribution, especially in tropical and subtropical regions, including SE United States and Appalachia • Caused by the human parasite Strongyloides stercoralis • Transmitted via direct contact with free-living larvae, usually through contaminated soil • Larvae penetrate skin migrate to intestine to mature into adult worms lay eggs develop into infective larvae in intestine • Infective larvae migrate toward the perianal opening • Penetrate skin Puthiyakunnon S, Boddu S, Li Y, et al. Strongyloidiasis-An Insight into Its Global Prevalence and Management. PLoS Negl Trop Dis. 2014 Aug; 8(8): e3018 www.cdc.gov/par asites STRONGLYLOIDIASIS • Most patients with strongyloidiasis are asymptomatic • Larval migration through skin (up to 10 cm/day) • Clinical features: • Urticarial serpiginous, raised, erythematous “tract” usually located on the buttocks or trunk • Autoinfection can cause the rash to recur for weeks to years • Hyperinfection with Strongyloides- diffuse petechiael “thumbprint purpura” eruption • Seen in immunocompromised individuals • Dermal invasion of a large number of larvae that migrate through vessel walls • High mortality www.cdc.gov/parasi tes www.visualdx.com STRONGLYLOIDIASIS • Recommended to treat all known infected patients, whether symptomatic or not • Consider testing patients at risk prior to initiating immunosuppressive drugs i.e. corticosteroids • Microscopic stool examination • Treatment options: • DOC: PO Ivermectin 0.2 mg/kg/day x 2 days (consider repeating in 2 weeks) • PO Albendazole 400 mg BID x 7 days • PO Thiabendazole 25 mg/kg BID x 2 days (7-10 days for hyperinfection syndrome) TRICHINOSIS • Worldwide distribution, including the United States • Caused by Trichinella spp. (most commonly Trichinella spiralis) • Transmission via ingestion of larva-containing cysts in raw or undercooked meat • Ingested larvae invade small bowel and mature into adult worms • Adult female worms release larvae that migrate to striated muscle and encyst (may remain viable for several years) • Disease severity categorized as light (1-10 ingested larvae), moderate (50-500 ingested larvae), or severe (>1000 ingested larvae) www.visualdx.com TRICHINOSIS • Pigs are the most common source of human infection • Typically from consumption of home-prepared sausage or undercooked wild game in the U.S. • Worldwide incidence has declined dramatically in past 2-3 decades • Improved pig-raising practices • Improved inspection processes • Commercial and home freezing of pork • Public awareness of danger of eating undercooked meats www.cdc.gov/para sites www.cdc.gov/parasites TRICHINOSIS • Nonspecific GI symptoms occur first (1-2 days post consumption) • Classic symptoms occur within 2 weeks of eating contaminated meat • Clinical features: • Myalgias (approx. 90% cases) • Periorbital edema • Nonpruritic morbilliform exanthem (uncommon) • Subungual splinter hemorrhages • Rare, severe cases may affect CNS, heart, and/or lungs death www.visualdx.com www.visualdx.com TRICHINOSIS • Self-limited if mild disease • Treatment options: • PO Corticosteroids- Prednisone 40-60 mg/day until symptoms