Hashimoto thyroiditis

Hashimoto Thyroiditis

Introduction

-Hashimoto thyroiditis is a common chronic autoimmune inflammatory disease 

-It is the most common  thyroid disorder in the United States

-it is the most common cause of hypothyroidism 

-it is caused by an autoimmune attack on the thyroid

-it is associated with a host of other autoimmune diseases 

-Autoantibodies in Hashimoto thyroiditis are  thyroglobulin antibody (Tg Ab), thyroidal peroxidase antibody (TPO Ab) and the TSH receptor–blocking antibody (TSH-R [block] Ab). 

-It shows female preponderance and is predominantly a disease of middle age 

-It is characterized by destruction of thyroid follicles and infiltration by lymphocytes and plasma cells interspersed by enlarged follicular epithelial oncocytic cells with abundant pink eosinophilic granular cytoplasm (Hürthle cells or Askanazy cells) 

-it is associated with an increased incidence of papillary carcinoma of the thyroid and primary thyroid lymphoma 

Symptoms & Signs 

-Diffusely enlarged, firm, rubbery, nontender and nodular thyroid which becomes smaller with the progression of the disease

-Some patients may develop hypothyroidism or rarely hyperthyroidism and exhibit their clinical manifestations 

Diagnosis 

Thyroid antibodies: Elevated antithyroglobulin and antithyroid peroxidase antibodies 

Laboratory findings vary based on thyroid status 

If patient is euthyroid: normal TSH and normal thyroid hormones 

if hypothyroid, elevated TSH and low thyroid hormones 

if hyperthyroid, suppressed TSH and elevated thyroid hormones 

FNAB: thyroid gland infiltrated by lymphocytes and Hürthle cells or Askanazy cells

Treatment 

Symptomatic/Cosmetic reasons: Surgery 

Hypothyroid status: Thyroid replacement therapy


Hyperprolactinemia

Introduction

Hyperprolactinemia is a condition of elevated prolactin level in blood 

-Prolactin is a pituitary hormone which acts to induce and maintain lactation and to decrease reproductive function and libido via via suppression of gonadotropin-releasing hormone [GnRH]

-Dopamine suppresses the production of prolactin from the anterior pituitary, so dopamine antagonists are associated with hyperprolactinemia

-The most common cause of hyperprolactinemia is a prolactin-secreting pituitary adenoma. Other causes are hypothyroidism, hypothalamic masses, 

and medications (risperidone, haloperidol, chlorpromazine, perphenazine, SSRIs, metoclopramide, opiates, H2 antagonists)

Symptoms & Signs

Men: Erectile dysfunction, loss of libido, gynecomastia, headaches, visual symptoms 

Women: loss of libido, amenorrhea, oligomenorrhea, infertility, irritability, anxiety, depression, galactorrhea and osteoporosis  

Diagnosis 

Labs: Fasting prolactin levels; labs to rule out other conditions such as hypothyroidism, pregnancy 

Imaging: Pituitary MRI

Treatment 

Dopamine agonists: Primary treatment of hyperprolactinemia; cabergoline, bromocriptine, or quinagolide

-Cabergoline is the preferred drug for the treatment of hyperprolactinemia because of greater efficacy and lower adverse effects

-Cabergoline can cause valvular heart disease 

Levothyroxine: if hypothyroidism is the cause of hyperprolactinemia 

Surgery: Transsphenoidal pituitary surgery for adenomas which are resistant to medical therapy 



Acromegaly & Gigantism

Introduction 

Acromegaly and gigantism are hormonal disorders caused by excessive growth hormone secretion usually due to a pituitary tumor 

-Acromegaly develops if excessive GH exposure occurs after closure of the long bone epiphyses (Adults = Acromegaly); where as gigantism develops if it occurs before closure of the epiphyses 

-Grown hormone hypersecretion leads to excessive generation of IGF-1, which acts as the mediator of most of the effects of GH 

-The average age at the time of diagnosis is 40 to 45 years 

Symptoms & Signs 

Facial Features: Frontal bossing, macroglossia, Jaw enlargement  (prognathism), widened teeth spacing 

Musculoskeletal features: Increased hat, shoe, glove and ring size; Enlargement of hands and feet with a doughy texture; arthropathy, carpal tunnel syndrome, kyphoscoliosis 

ENT: Large fleshy nose, deepening of the voice, snoring 

Skin: Doughy texture, cutis verticis gyrata, acanthosis nigricans, skin tags, thick heel pads, hyperhidrosis, hirsutism 

Eyes: Bitemporal hemianopsia (due to optic chiasm compression from the tumor) 

Associated conditions: Diabetes, hypertension, glucose intolerance, cardiomyopathy, left ventricular hypertrophy, diastolic dysfunction

Diagnosis 

Insulin-like growth factor – 1 : Elevated levels 

Growth hormone: Elevated levels in serial measurements; Failure to suppress Growth hormone levels by oral glucose-tolerance test 

Imaging: MRI of the pituitary may show macroadenoma 

Treatment 

Surgery: Removal of adenoma by transsphenoidal surgery 

Somatostatin analogues: Octreotide, lanreotide, pasireotide

Dopamine agonists: Bromocriptine, cabergoline 

GH receptor antagonist: Pegvisomant  

Radiation: Pituitary irradiation 

Q. What is the most important requirement for diagnosis of GH excess? Demonstration of unsuppressable GH secretion 


Chromoblastomycosis

Introduction 

Chromoblastomycosis is a chronic progressive subcutaneous mycosis caused by multiple species of pigmented fungi, known as melanized or ‘dematiaceous’ fungi, mainly the Fonsecaea, Phialophora, or Cladosporium species

-the fungi appear as brown, thick-walled, spherical, septal cells in tissues (Medlar bodies or muriform cells) 

-it usually affects older male agricultural workers 

-it typically occurs on the foot or leg, arms or trunk following tissue injury due to trauma  

-it occurs in the Americas, Africa (particularly Madagascar), and South Asia 

Symptoms & Signs 

-the fungus forms thick-walled single cells or cell clusters (sclerotic or muriform bodies), which may transform into papules, scaly, wart-like structures resembling the tips of a cauliflower, and verrucous plaques with satellite lesions 

Diagnosis 

Histology: brown-pigmented, thick double-walled, multiseptate, melanized sclerotic, globose structures called muriform bodies. 

Culture: fungi grow as darkly pigmented black colonies with a downy surface 

Treatment 

Antifungals: Itraconazole,voriconazole, terbinafine, flucytosine, amphotericin Procedures: Cryotherapy, curettage, electrodessication, and surgical excision


Talaromyces or Penicilliosis

Introduction 

Penicilliosis is a tuberculosis-like fungal disease caused by Talaromyces (formerly Penicillium) marneffei

It is most common in northeastern India, Thailand, Vietnam,Taiwan, China, and Hong Kong

-it most often affects patients with advanced HIV

-it is a dimorphic fungus; grows as a mold that produces a distinctive rose-colored pigment and as yeast-like cells that reproduce with septal formation 

-it is acquired by spore inhalation

Symptoms & Signs 

-It usually presents as a pulmonary disease or disseminated disease 

-Fever, fatigue, cough, weight loss, lymphadenopathy, hepatosplenomegaly, generalized umbilicated papular rash resembling molluscum contagiosum 

Diagnosis 

The diagnosis is made by culture or by histology 

-it forms characteristic yeast-like cells which are divided by a septum and produce a characteristic red pigment

Treatment 

The treatment of choice consists of amphotericin B followed by itraconazole 


Sporotrichosis

Introduction 

Sporotrichosis is a chronic granulomatous fungal infection caused by Sporothrix schenckii

-it is common among gardeners, florists and agriculture workers 

-Infection occurs when the organism is inoculated into the skin during gardening or puncture from a rose thorn 

S. schenckii is a thermally dimorphic fungus which produces branching, septate hyphae and conidia 

Symptoms & Signs 

Sporotrichosis has four clinical presentations: 

Fixed: a painless nodule or plaque that may become pustular or ulcerated or verrucous plaque; most common on dorsum of hand or finger

Lymphocutaneous:  Erythematous nodules in a linear array in lymphatic channels mostly on the dorsum of the hand and forearm

Pulmonary: inhalation of conidiospores producing pulmonary infection 

Disseminated:  From lungs,it disseminates hematogenously to joints, eyes and meninges 

Diagnosis 

Histology: Granulomatous microabscesses 

Culture: Most reliable method of diagnosis 

Treatment 

Itraconazole, fluconazole, terbinafine, Amphotericin B, potassium iodide 


Paracoccidioides

Introduction

-Paracoccidioidomycosis is a subacute or chronic systemic mycosis caused by Paracoccidioides brasiliensis

-It occurs in rural areas of South and Central America, thus known as South American blastomycosis

-It is a dimorphic fungus that exists as a mold in soil and as a yeast in tissue

-The mold produces chlamydospores and conidia which enter human body mainly by inhalation 

Symptoms & Signs 

Asymptomatic form: marked by long asymptomatic periods 

Pulmonary form: Cough, weight loss, pulmonary granulomas 

Mucocutaneous form: Oropharyngeal lesions are the most common sign on physical examination; they present as small granulomas or painful ulcers over the nose, conjunctivae, mouth, gingiva, lips, pharynx, larynx (dysphonia) or anus 

Lymphatic form: Lymphadenopathy, ulceration, draining sinuses 

Diagnosis 

Histology: Granulomas with central caseation with fibrosis 

Culture: A parent round yeast cell surrounded by large numbers of small buds described as ‘Ship captain’s wheel’ 

Serology: antigen detection, antibodies to paracoccidioidin 

Treatment 

Effective agents: Itraconazole (the drug of choice), Voriconazole, ketoconazole, trimethoprim-sulfamethoxazole and Amphotericin B 


Blastomycosis

Blastomycosis

Introduction 

Blastomycosis is a fungal infection caused by inhaling Blastomyces dermatitidis

-B. dermatitidis is a dimorphic fungus that exists as a mold in soil and as a yeast in tissue

-In the United States, it is endemic in the states bordering the Great Lakes and in the Mississippi River basin

-Its geographic location is similar to that of histoplasmosis 

-in soil it forms hyphae with small pear-shaped conidia

-Infections occur from inhalation of aerosolized conidia, which transform to the yeast phase in the lungs 

Symptoms & Signs 

-The most common sites of involvement in blastomycosis are lung, skin, bone, genitourinary tract, and central nervous system

Lungs: chief sites of involvement; may cause lobar pneumonia indistinguishable from bacterial pneumonia; fever, chills, cough, chest pain, and dyspnea 

Skin: the most common extrapulmonary form of blastomycosis; either verrucous or ulcerated in appearance

Bone: osteomyelitis frequently affecting the ribs and vertebrae 

Genitourinary tract:  causes epididymitis, prostatitis, and urethritis

CNS: causes meningitis, mass lesions, or brain abscess

Diagnosis 

Histology:  Rounded, double walled, spherical cells with broad-based buds (Cryptococcus neoformans forms a narrow-based bud)

Culture: most reliable; Hyaline branching septate hyphae with small pear-shaped conidia

Serology: detects Blastomyces antigen in urine and serum 

Imaging: Lobar consolidation on CXR or CT Chest

Treatment 

Itraconazole (the drug of choice), Voriconazole, Posaconazole, and Amphotericin B 


Aspergillosis

Introduction 

Aspergillosis is a spectrum of diseases caused by Aspergillus species, most commonly by Aspergillus fumigatus 

-it is the most common invasive fungal infection in transplant recipients and in patients with hematologic cancer 

-it produces small conidia which are inhaled; following inhalation conidia germinate to produce hyphae that invade the lungs and other tissues 

Symptoms & Signs 

 The lungs, sinuses, brain and skin are the organs most often involved.

Allergic bronchopulmonary aspergillosis (ABPA): 

-ABPA is a hypersensitivity reaction to the presence of Aspergillus in the bronchi

-Dyspnea, wheezing, cough, malaise, fever, hemoptysis, bronchiectasis

-Characteristic radiographic finds: “Tramline shadows” (parallel linear shadows); “finger in glove” opacity (due to mucoid impaction in dilated bronchi); “toothpaste shadows” (due to mucoid impaction of the bronchi); “ring shadows” (due to dilated bronchi) 

-The screening test for ABPA is a skin prick test with Aspergillus antigens

Severe Asthma with Fungal Sensitivity 

Pneumonia 

-The most common syndrome associated with aspergillosis is pneumonia

-Fever, chest pain, cough, hemoptysis 

-Aspergilli have remarkable ability to grow in lung cavities created by tuberculosis; within the cavities, they produce radiopaque aspergillomas (fungus balls) 

Sinuses 

-Aspergillus is the most common cause of fungal sinusitis

-Fever, headache, sinus discharge, epistaxis, tissue destruction, necrotic lesions in the nose or palate

Brain 

-Disseminated aspergillosis can spread to the brain

-headache, fever, neck rigidity, mental status changes 

Skin  

-Erythematous plaques progressing to necrotic ulcers with black eschars 

Diagnosis 

Biopsy: Septate, branching hyphae with radiating chains of conidia in V or Y shaped branches 

Serology: Detection of Aspergillus antigens, Galactomannan and 1,3-β-D-glucan

Treatment 

Antifungal drugs: Voriconazole, posaconazole, itraconazole, isavuconazole, micafungin, caspofungin, and amphotericin B 

ABPA: Systemic corticosteroids, antifungals 


cryptococcosis

Introduction 

Cryptococcosis is a subacute or chronic infection caused by Cryptococcus neoformans, an encapsulated budding yeast

-Cryptococcal cells are typically present in bird droppings, particularly pigeon droppings 

C. neoformans is a yeast that is characterized by a thick polysaccharide capsule. 

-Polysaccharide capsule is the major virulence factor and basis for antigen testing

-it is most common cause of fungal meningitis

-Cryptococcosis is acquired by inhaling aerosols containing the yeast, which disseminate to other organs via blood 

Symptoms & Signs 

-The most common sites of infection are the lungs, central nervous system and skin 

Pulmonary cryptococcosis 

it is often asymptomatic or may cause an influenza-like illness with cough, fever, chest pain and dyspnea 

Meningoencephalitis

-Meningitis is the most commonly recognized and most serious form of cryptococcal disease

-In immunocompetent patients, it takes a slow, indolent course but in immunocompromised patients, it takes a more rapid course 

-Headache, fever, nausea, vomiting, neck stiffness, dizziness, somnolence, irritability, confusion, photophobia, seizures, cranial nerve defects, confusion, mental status changes

Cryptococcal skin disease: 

Cryptococcal cellulitis: resembles bacterial cellulitis, red, hot, tender plaques 

Cryptococcal dermatitis: resembles molluscum contagiosum, papular, nodular lesions with central umbilication 

Immune Reconstitution Syndrome

-A paradoxical clinical worsening which comes with enhanced inflammatory response due to immune reconstitution 

-worsening meningitis, increased intracranial pressure, hypercalcemia 

Diagnosis 

Histopathology and Cytology: globose or oval to lemon-shaped yeast with a polysaccharide capsule after staining with India ink, Gomori methenamine silver (GMS) and periodic acid–Schiff (PAS) stain, Mayer’s mucicarmine stain, and Masson–Fontana melanin stain; On diphenolic substrate, the phenol oxidase of cryptococcus produces melanin in the cell walls producing brownish colored colonies 

Antigen detection:  detection of Cryptococcal capsular antigen in serum, CSF, pleural fluid  

Culture: whitish mucoid colonies with spherical budding yeast cells surrounded by a thick non-staining capsule 

CSF: increased opening pressure, increased protein, decreased glucose, presence of cryptococcal capsular antigen

Imaging: Cryptococcal granulomatous calcifications on CXR; cryptococcomas in the brain on MRI, CT scan 

Treatment 

Pneumonia: Fluconazole, itraconazole, voriconazole, posaconazole

Meningitis: Amphotericin B, Fluconazole



Pneumocystis pneumonia

Introduction 

-Pneumocystis pneumonia is caused by Pneumocystis jirovecii, previously known as Pneumocystis carinii 

-it was previously thought to be a protozoan, but now recognized as a fungus

-it is an extracellular pathogen 

-It has morphologically distinct forms: thin-walled trophozoites and thick-walled cysts 

-It is the most frequent serious complication of HIV infection in the United States

–it is the most common opportunistic infection among AIDS patients

-It is the most common identifiable cause of death in patients with AIDS

Symptoms & Signs 

-In the absence of immunosuppression, P. jiroveci does not cause disease

-It can cause disease in patients with immunocompromised conditions – AIDS, or organ transplantation, and chemotherapy 

– PCP is often the initial opportunistic infection that establishes the diagnosis of AIDS, often when the CD4+ T-lymphocyte count has fallen below 200 cells/mm3

-non-productive cough out of proportion to physical findings, fever, fatigue, weight loss, dyspnea, marked hypoxemia, and spontaneous pneumothorax

Diagnosis 

Diagnostic techniques: Routine sputum, induced sputum, transtracheal aspiration, Bronchoalveolar lavage, transbronchial biopsy, open lung biopsy, needle aspirate 

Histology: Alveoli filled with trophozoites, cysts, alveolar cells, monocytes, producing a distinctive foamy, honeycombed appearance 

Commonly used Stains: Giemsa, toluidine blue, methenamine silver, calcofluor white

Serology: measurement of 1-3 β-d-glucan levels, hypoxia, elevated LDH

Imaging: 

CXR: Diffuse, interstitial infiltration with classic “butterfly” pattern

CT Scan lung: bilateral patchy and ground-glass opacities and tree-in-bud nodular opacities

Treatment 

First-line therapeutic agent: Trimethoprim-sulfamethoxazole 

Other effective agents: Adjunctive corticosteroid therapy, Pentamidine, Clindamycin + Primaquine, dapsone, atovaquone 


Coccidioidomycosis

Introduction 

-Coccidioidomycosis is caused by dimorphic soil-dwelling fungi of the genus Coccidioides

-it is endemic in the arid regions of the southwestern United States, Central America, and South America

-Coccidioides grow in nature as a mold composed of barrel-shaped arthroconidia

-Infection occurs after inhalation of arthroconidia which will develop into large multinucleated spherical structures called spherules, which undergo division to release endospores 

Symptoms & Signs 

-Infection is usually self-limited in 60% of individuals 

-In the symptomatic, it takes the following clinical manifestations 

Valley fever, San Joaquin Valley fever, or desert rheumatism: the most common presentation; influenza-like or pneumonia like illness; fever, night sweats, profound fatigue, cough, headache, malaise, pleuritic chest pain, arthralgia, peripheral eosinophilia, hilar or mediastinal lymphadenopathy

Coccidioidal CNS disease: headache, fever, altered mental status, typically basilar meningitis, cranial nerve deficits 

Coccidioidal Skin Disease: most common form of disseminated disease, classic lesions seen on the nasolabial fold and sternoclavicular area, appears as papules, nodules, or verrucous plaques, ulcers, draining sinuses, abscesses, maculopapular rash (toxic erythema), erythema nodosum typically over the lower extremities, erythema multiforme, usually in a necklace distribution 

Coccidioidal joint disease: Joint pains and swellings often of the knees and ankles 

Diagnosis 

Microscopy: Large spherules containing endospores 

Culture: White to tan cottony colony formation, barrel-shaped arthroconidia
Serology: the mainstay of diagnosis, two serologic assays are used: The tube precipitin-reacting antigen detects IgM antibodies; The complement-fixing (CF) antigen detects IgG antibodies

Imaging: Patchy, nodular, lobar pulmonary infiltrates, hilar lymphadenopathy, mediastinal lymphadenopathy 

Treatment 

Mild disease: No treatment Severe disease: Amphotericin b, itraconazole, fluconazole, voriconazole, posaconazole


Histoplasmosis

Introduction 

Histoplasmosis is caused by Histoplasma capsulatum, an unencapsulated, dimorphic fungus, which has affinity to grow in soil containing bird or bat droppings 

-it is seen in Africa, India, Far East, the Ohio River and Mississippi River valleys in America, Canada 

-Histoplasmosis is the most prevalent endemic mycosis in North America

-mode of infection is usually the inhalation of mold microconidia 

Symptoms & Signs 

-Most patients are asymptomatic 

-In symptomatic, it takes the following forms which can overlap 

Acute Pulmonary Histoplasmosis: Fever, cough, chest pain, myalgias, arthralgias, arthritis, rash – toxic erythema, erythema multiforme, or erythema nodosum, pericarditis, mediastinitis; Chest radiographs usually show diffuse interstitial pattern 
Chronic Pulmonary Histoplasmosis: Upper lobe infiltrates, pulmonary consolidation and cavitation, closely resembling tuberculosis

Acute Progressive Disseminated Histoplasmosis: Dissemination to organs such as the liver, spleen, bone marrow, and lymphoreticular system; progressive weight loss, fever,anemia, hepatosplenomegaly; diffuse micronodular pulmonary infiltrates; common in AIDS patients

Chronic Progressive Disseminated Histoplasmosis: Oral or pharyngeal ulceration, hepatosplenomegaly, adrenal insufficiency (Addison disease) 

Cutaneous histoplasmosis: Guttate psoriasis-like papules, pustules, chronic ulcers, plaques, panniculitis 

Diagnosis 

Fungal culture (gold standard): identification of small, oval shaped, intracellular yeast-like cells of Histoplasma within macrophages in sputum, blood, bone marrow or biopsy specimens 

Serology: detection of antibodies to histoplasmin or the yeast cells; 

Urine: Histoplasmosis antigen testing 

Skin test: Histoplasmin skin test

Treatment 

Amphotericin B, Itraconazole, Voriconazole, Posaconazole, isavuconazole 


candidiasis

Introduction 

Candidiasis is a fungal infection caused by a yeast (a type of fungus) called Candida

-the most common species is Candida albicans

-Candida albicans can exist in both hyphal and yeast forms (dimorphism)

-It can form hyphae and pseudohyphae 

-Risk factors: use of oral antibiotics, use of steroids, immunodeficiency, diabetes, pregnancy, birth control pills, obesity and trauma 

Symptoms & Signs 

-It can appear in different manifestations: Cutaneous candidiasis, oral candidiasis, paronychia, onychomycosis, vulvovaginitis, balanitis, chronic mucocutaneous candidiasis, and disseminated candidiasis 

Morphology: Macules, beefy-red patches, plaques with satellite papules and pustules at the periphery 

Oral thrush: Whitish-curd-like pseudomembranous lesions over an erythematous base; it “wipes off” with the application of gauze 

Onychomycosis: Erythematous swelling of the nail folds 

Diagnosis 

Clinical features: Whitish, curd-like pseudomembranes

Potassium hydroxide (KOH) preparation: pseudohyphae and budding yeasts

-Candida albicans also shows true hyphae as germ tubes or chlamydospores

Other tests: Blood cultures, antigen and antibody testing, β-D-glucan tests 

Treatment 

Therapy for candidiasis includes three classes of medications:

1.Azoles: Ketoconazole, Fluconazole,miconazole, clotrimazole, itraconazole, posaconazole, isavuconazole, voriconazole

2.Echinocandins: Caspofungin, Anidulafungin, Micafungin 

3.Polyenes: Amphotericin B 

Mild disease: Nystatin or azoles 

Severe disease: Azoles or echinocandins or amphotericin B


Loiasis

Introduction 

Loiasis is a chronic filarial disease caused by infection with Loa loa (African eye worm) 

-the disease is found in the rainforests of West and Central Africa

-it is transmitted by the bite of the deer fly or mango fly called Chrysops 

-Infected larvae deposited by the bite of the deer fly crawl into the skin and develop into adults which migrate subcutaneously. Females produce microfilariae, which enter the blood 

-it is the adult worm rather than the microfilariae which produce clinical manifestations 

Symptoms & Signs 

Many infected persons are asymptomatic 

Skin: the characteristic finding of loiasis is the Calabar swelling, localized subcutaneous area of angioedema, erythema, pain and pruritis developing on the extremities due to migration of adult worms through subcutaneous tissues 

Eye: Adult worms crawling across the conjunctiva of the eye, scary but no loss of vision 

Blood: Peripheral eosinophilia, leukocytosis and elevated IgE levels 

Diagnosis 

Detection of microfilariae in the blood: peak circulation between 10 A.M and 2:00 P.M; so a daytime blood smear should be obtained 

Isolation of the adult worm from the eye or skin biopsy 

Treatment 

The treatment of choice is diethylcarbamazine

Worms in the eyes: surgical excision  


Onchocerciasis

Introduction

Onchocerciasis is a chronic parasitic disease caused by filarial nematode Onchocerca volvulus 

-it is transmitted by female blackflies near free-flowing rivers and streams 

-Most cases are in tropical Africa and Central America 

-Larvae deposited by the blackfly mature into adult worms in subcutaneous tissue and form skin nodules. Females produce microfilariae which migrate to the eyes and cause serious eye disorders. 

Symptoms & Signs 

Onchocerciasis is characterized by dermal, ocular and lymphatic manifestations

Dermal: Subcutaneous nodules over bony prominences (onchocercomata), intensely pruritic papular rash, skin atrophy, scaly dermatitis feeling like ‘lizard skin’ or ‘leopard skin’, loose pelvic skin described as ‘hanging groin’ 

Ocular: most serious manifestations of onchocerciasis; photophobia,   conjunctivitis, keratitis, uveitis, retinochoroiditis, iridocyclitis, optic atrophy, glaucoma, and blindness (river blindness) 

Lymphatic: Inguinal and femoral lymphadenopathy

Diagnosis 

Identification of microfilariae: in skin snips, in nodule biopsy or in the urine, but not in blood 

Eye: Slit-lamp examination revealing microfilariae in the eye 

Mazzotti test: Exacerbation of skin rash and pruritus after administration of diethylcarbamazine 

Other tests: PCR

Treatment 

-Ivermectin (drug of choice) kills microfilariae, not adult worms 

-Suramin kills adult worms 

Other agents: Moxidectin, doxycycline 


Lymphatic filariasis

Filarial infections are grouped into 3 categories of disease based on the location of disease: lymphatic, cutaneous, and body cavity

-Lymphatic filariasis is caused by three filarial nematodes: Wuchereria bancrofti (most common), Brugia malayi, and Brugia timori

-it is found mostly in South Asia and Africa 

-Humans are infected by the bites of infected mosquitoes

-Larvae move to the lymphatics and lymph nodes, where they mature into adult worms, which produce large numbers of microfilariae

Symptoms & Signs 

-Classical lesion: Lymphadenitis in the femoral area as a red, enlarged and tender lump spreading centrifugally down the lymphatic channels of the leg (centripetal spread in bacterial lymphangitis) 

-recurrent bouts of “filarial fevers” lasting 2 to 3 weeks

-High fever, transient local edema, lymphatic inflammation – Acute adenolymphangitis (ADL)

-Elephantiasis, thickening of the subcutaneous tissues, brawny edema

-Conjunctivitis, headache, photophobia, vertigo, scrotal pain, orchitis, epididymitis, elephantiasis of breasts, vulva 

Diagnosis 

Detection of microfilariae in peripheral blood, hydrocele fluid; Periodicity determines the best time for blood collection;  blood samples for Wuchereria and Brugia are only positive if drawn at night

Serology: Antigen assays, PCR 

High-frequency ultrasound: can show motile adult worms 

Treatment 

Effective agents: Diethylcarbamazine (Drug of choice), Albendazole, Doxycycline, ivermectin 

Diethylcarbamazine can cause hypersensitivity reaction with antigen liberation from dead microfilariae 


Anisakiasis

Introduction 

-Anisakiasis is a gastrointestinal parasitic disease caused by the larvae of the nematode, Anisakis simplex

-Transmission is due to ingestion of infective larvae from saltwater fish or squid that humans eat raw or undercooked sushi or sashimi or ceviche 

-it is most common in Japan

-Adult worms live in whales and dolphins 

Symptoms & Signs 

Acute infection can resemble appendicitis, and chronic infection can resemble gastrointestinal cancer

Severe epigastric or abdominal pain, nausea, vomiting, urticaria, angioedema, anaphylaxis 

Diagnosis 

Clinical: Acute abdomen after ingestion of raw fish 

Endoscopy: Direct visualization of larvae 

Biopsy: Eosinophilic granuloma with embedded larvae 

Treatment 

-No medical treatment is available 

-Surgical or endoscopic removal by extraction of the larvae 


Toxocariasis

Introduction 

Toxocariasis is due to human infection with Toxocara cati (an intestinal parasite of cats) or Toxocara canis (an intestinal parasite of dogs)

-Most commonly encountered among children 1 to 6 years of age 

-Transmission to humans by ingestion of eggs in soil, particularly in those with a history of pica

-Invading larvae migrate in human tissues and cannot mature to adult worms 

Symptoms & Signs 

A. Visceral larva migrans: it is due to disseminated systemic infection; It mostly affects the liver, lungs, heart, skeletal muscle and brain; eosinophilic granulomas surround parasite larvae

Pulmonary: Cough, wheezing, pulmonary infiltrates 

Abdominal: The most commonly affected organ is the liver; hepatomegaly, splenomegaly 

Heart: Myocarditis, pericarditis, cardiac arrhythmia

decreased visual acuity 

B. Ocular Larva Migrans

Unilateral posterior or peripheral inflammatory eye mass, granuloma formation, blurred vision, red eye, a whitish pupil due to loss of red reflex (leukocoria), unilateral strabismus

Diagnosis 

Labs: Leukocytosis with marked eosinophilia, anemia, and elevated liver function tests

Serology: ELISA, Western blot 

Liver biopsy: Demonstration of larva 

Treatment 

-It is usually a benign and self-limited illness 

-Severe disease: Albendazole, mebendazole, corticosteroids 


ANGIOSTRONGYLIASIS

Introduction 

Angiostrongyliasis is a parasitic disease caused by Angiostrongylus cantonensis and Angiostrongylus costaricensis

-They possess distinctive, coiled pattern due to their uterine tubes 

-Angiostrongylus cantonensis, the rat lungworm, is the most common cause of human eosinophilic meningitis

-it is transmitted between rats and mollusks (such as slugs or snails) in its natural life cycle

-Most cases of infection are diagnosed in Southeast Asia and the Pacific Basin,

-Humans acquire the Infection by ingesting raw or undercooked infected snails or slugs or foods contaminated by the slime of infected snails or slugs 

Symptoms & Signs 

Meningeal Angiostrongyliasis: Eosinophilic meningitis caused by Angiostrongylus cantonensis; headaches,nausea, vomiting, neck stiffness, cranial and extraocular nerve palsies, seizures, paralysis, lethargy 

Abdominal Angiostrongyliasis: caused by Angiostrongylus costaricensis; mimics appendicitis; nausea, vomiting, fever, abdominal pain  

Diagnosis 

Diagnosis is based on epidemiologic history, clinical features and labs 

Labs: Eosinophilia 

Epidemiologic history: History of travel to endemic regions, of eating snails and slugs 

Treatment 

There is no specific treatment for Angiostrongyliasis