Appendix A Signs and Symptoms of Arthropod-Borne Diseases The following is an alphabetical listing of common signs and symptoms of arthropod-borne diseases. Unfortunately, few signs and symptoms are specific to anyone disease. Further differen­ tiation by appropriate laboratory or radiologic tests may be needed. By no means should this listing be considered as a com­ plete differential diagnosis of any of the symptoms discussed. Adenopathy: Generalized adenopathy may occur in the early stages of African trypanosomiasis-the glands of the poste­ rior cervical triangle being most conspicuously affected (Winterbottom's sign). Adenopathy may also be seen in the acute stage of Chagas' disease. Anemia: Anemia may be seen in cases of malaria, babesiosis, and trypanosomiasis. Anemia can be especially severe in falciparum malaria. Blister: A blister may occur at arthropod bite sites. Blistering may also occur as a result from blister beetles contacting human skin. Bulls-Eye Rash (See Erythema Migrans) Chagoma: An indurated, erythematous lesion may occur on the body-often head or neck-caused by Trypanosoma cruzi infection (Chagas'disease). A chagoma may persist for 2-3 mo. Chyluria: The presence of chyle (lymphatic fluid) in the urine is often seen in lymphatic filariasis. Urine may be milky white and even contain microfilariae. Coma: Sudden coma in a person returning from a malarious area may indicate cerebral malaria. African trypanosomia­ sis (sleeping sickness) may also lead to coma after a long period of increasingly severe symptoms of meningoencepha­ litis. Rocky Mountain Spotted Fever and other rickettsial infections may also lead to coma. 203 204 Infectious Diseases and Arthropods Conjunctivitis: Chagas' disease and onchocerciasis may lead to chronic conjunctivitis. Dermatitis: Several arthropods may directly or indirectly cause dermatitis. Chiggers and other mites may attack the skin, causing a maculopapular rash. Scabies mites may burrow under the skin's surface making itchy trails or papules. Lice may give rise to hypersensitivity reactions with itchy pap­ ules. Chigoe fleas burrow in the skin (especially on the feet), causing local irritation and itching. Macules or erythema­ tous nodules may result as a secondary cutaneous manifes­ tation of leishmaniasis. Diarrhea: Leishmaniasis (and specifically visceral leishmania­ sis-kala-azar) may lead to mucosal ulceration and diarrhea. In falciparum malaria, plugging of mucosal capillaries with parasitized red blood cells may lead to watery diarrhea. Edema: Edema may result from arthropod bites or stings. Loia­ sis (a nematode worm transmitted by deer flies) may also cause edema-a unilateral circumorbital edema as the adult worm passes across the eyeball or lid. Passage of the worm is brief, but inflammatory changes in the eye may last for days. Loiasis may also lead to temporary appearance of large swellings on the limbs, known as Calabar swellings at the sites where migrating adult worms occur. Unilateral edema of the eyelid, called Romana's sign, may occur in Chagas' disease. African trypanosomiasis (sleeping sickness) may result in edema of the hips, legs, hands and face. Elephantiasis: Hypertrophy and thickening of tissues, lead­ ing to an "elephant leg" appearance, may result from lym­ phatic filariasis. Various tissues may be affected, including limbs, the scrotum, and the vulva. Eosinophilia: Helminth worms may cause eosinophilia. Atopic diseases, such as rhinitis, asthma, and hay fever also are characterized by eosinophilia. Eosinophilic Cerebrospinal Fluid Pleocytosis: Cerebrospinal fluid eosinophilic pleocytosis can be caused by a number of infectious diseases (including rickettsial and viral infec­ tions), but is primarily associated with parasitic infections. Epididymitis: Epididymitis, with orchitis, may be an early complication of lymphatic filariaisis. Erythema Migrans: Erythema migrans may follow bites of ticks infected with the causative agent of Lyme disease, Bor- Signs and Symptoms 205 relia burgdorferi. Typically the lesion consists of an annular erythema with a central clearing surrounded by a red migrating border. Although erythema migrans does not always occur, it is virtually pathognomonic for Lyme disease. Eschar: A round (generally 5-15 mm) spot of necrosis may result from boutonneuse fever (a spotted fever group ill­ ness) or scrub typhus. An eschar develops at the site of tick or chigger bite. Excoriation: Lesions produced by "self-scratching" may be a sign of imaginary insect or mite infestations (delusions of parasitosis). Fever: Fever is a common sign of many arthropod-borne diseases, including the rickettsioses, thyphus, dengue, yellow fever, plague, the encephalitides, and others. In some cases, there are cyclical peaks of fever, such as in relapsing fever (tick-borne) or malaria. Falciparum malaria is notorious for causing extremely high fever (107°F or higher). Filariasis may be marked by fever, especially early in the course of infection. Hematemesis: Coffee-ground color or black vomit may be a sign of yellow fever. Hemoglobinuria: Falciparum malaria can cause "blackwater fever." Hydrocele: Hydrocele may result from lymphatic filariasis, developing as a sequel to repeated attacks of orchitis. Kerititis: Inflammation of the cornea is sometimes a result of ocular migration of Onchocerca volvulus microfilariae. It may lead to blindness. Leukopenia: Leukopenia is a prominent finding in cases of ehrlichiosis. It may also occur (3000-6000/ mm3) with a rela­ tive monocytosis during the afebrile periods of malaria. Lymphadenitis: Inflammation of one or more lymph nodes may be a sign of lymphatic filariasis-especially involving the femoral, inguinal, axillary, or epitrochlear nodes. Lymphangitis: Lymphangitis can be an early symptom of lym­ phatic filariasis, involving the limbs, breast, or scrotum. Lymphocytosis: Lymphocytosis may occur in Chagas' disease. Maggots: The presence of fly larvae in human tissues is termed myiasis. Various blow flies, bot flies, and other muscoid flies are usually involved. Meningoencephalitis: Meningoencephalitis has many causes, but may be a result of trypanosomes in the case of African 206 Infectious Diseases and Arthropods trypanosomiasis (sleeping sickness) or Chagas' disease (although generally milder). Falciparum malaria infection may be cerebral, with increasing headache and drowsiness over several days, or even sudden onset of coma. Myocarditis: Chagas' disease may lead to myocardial infec­ tion. African trypanosomiasis may also cause myocarditis to a lesser extent. Neuritis: Neuritis may be caused by bee, ant, or wasp venom. Occasionally stings to an extremity result in weakness, numbness, tingling, and prickling sensations for days or weeks. Neuritis may also result from infection with the Lyme disease spirochete. Nodules, Subcutaneous: Onchocerciasis may present as skin nodules (see Onchocercoma). Tick bites may also result in nodules. Fly larvae in the skin (myiasis) may also present as nodules. Common species involved are the human bot­ fly larva, Dermatobia hominis, the Tumbu fly, Cordylobia anthropophaga, and rodent botfly larvae, Cuterebra spp. Onchocercoma: Coiled masses of adult O. volvulus worms beneath the skin enclosed by fibrous tissues may occur in patients living in tropical countries endemic for ochocerciasis. Orchitis: Orchitis may be a symptom of lymphatic filariasis; repeated attacks may lead to hydrocele. Paralysis: Ascending flaccid paralysis may result from tick attachment. The paralysis is believed to be caused by a sali­ vary toxin injected as the tick feeds. Proteinuria: Proteinuria, with hyaline and granular casts in the urine, often occurs in falciparum malaria. Puncta: A small, point-like pierce mark may mark the bite or sting site of an arthropod. Paired puncta may indicate spi­ der bite or centipede bite. Rash: There are myriad causes of rash, but rash may accom­ pany many arthropod-borne diseases, such as Rocky Moun­ tain Spotted Fever, ehrlichiosis, murine typhus, and African trypanosomiasis. The rash may appear to be ring-like, and expanding in the case of Lyme disease (see Erythema Migrans). An allergic urticarial rash may be seen in the case of bites or stings. Romana's Sign: A common sign early in the course of Chagas' disease, Romafia's sign is a unilateral palpebral edema, involving both the upper and lower eyelids. This generally Signs and Symptoms 207 occurs when a kissing bug (the vector of the Chagas' organsism) bites near the eye. Shock: Shock may occur from arthropod stings (rarely bites) as a result of hypersensitivity reactions to venom or saliva. Shock may also accompany falciparum malaria. Splenomegaly: Splenomegaly can be a result of lymphoid hyperplasia in both African and American trypanosomia­ sis. It may also occur in visceral leishmaniasis (kala-azar). Tachycardia: Both African and American trypanosomiasis may produce tachycardia. In Chagas' disease tachycardia may persist into the chronic stage where it may be associated with heart block. Ulcers, Cutaneous: A shallow ulcer (slow to heal) may be a sign of cutaneous leishmaniasis. In the New World,lesions from cutaneous leishmaniasis are most often found on the ear. Also, a firm, tender, raised lesion up to 2 cm or more in diameter may occur at the site of infection in African trypa­ nosomiasis. Urticaria: Urticaria may result from an allergic or generalized systemic reaction to arthropod venom or (more rarely) saliva. Verruga Peruana: A benign dermal eruption (peruvian warts) is one manifestation of bartonellosis.