Fungal Infections

Question 1

What causes tinea versicolor?

Answer 1

Superficial yeast infection caused by Pityrosporum ovale aka Malassezia furur. Organism oxidizes fatty acids in the skin and inhibits tyrosinase in the melanocytes leading to loss of pigmentation

Question 2

What is the clinical presentation of tinea versicolor?

Answer 2

Velvety tan, pink or white macules. Hypopigmented areas that do not tan with the rest of the skin. trunk, upper arms, neck and groin. Lesions may scale if scraped

Question 3

What are laboratory findings of tinea versicolor?

Answer 3

Skin scrapings seen on KOH prep show budding spores and large hyphae “spaghetti and meatballs”

Question 4

What are treatment options of tinea versicolor?

Answer 4

Selenium sulfide lotion 2.5% (Rx) apply once daily for 7 days. Apply with a cotton ball, allow to dry 15 min prior to bathing. To prevent recurrence maintenance therapy twice a month

Question 5

What are tinea infections?

Answer 5

located in the stratum corneum and caused by dermatophytes. dermtophytes digest keratin leading to scaling, nails thicken/crumble, hair loss.

Question 6

How is tinea diagnosed?

Answer 6

Microscopic evaluation-Skin margin scraping and KOH prep. Fungal culture-Takes 2 weeks

Question 7

What is the presentation and treatment of tinea corporis?

Answer 7

Ring shaped lesion with well-demarcated margins. Central clearing. Scaly, erythematous border. Treat with a topical azole antifungal (apply 1-2 x daily for 2-4 weeks)

Question 8

What is the presentation and treatment of tinea cruris?

Answer 8

located in groin, inguinal folds. Borders distinct. Lesions large, erythematous. Macular with central clearing. Hallmark: pruritus with burning. Treatment: topical azole antifungal

Question 9

What is the presentation and treatment of tinea pedis?

Answer 9

scaling, maceration, fissures b/w toes, diffuse scaling of the soles. vesicles and bullae on the sole of the foot, great toe and instep. Treatment: topical azole antifungal

Question 10

What is the presentation and treatment of tinea capitis?

Answer 10

Most cases in children. Inflamed scaly, alopecic patches. Tender, pustular nodules. Treatment: griseofulvin for 8 weeks

Question 11

What is the presentation and treatment of tinea unguium (onychomycosis)?

Answer 11

Typically toenails but can affect fingernails. Onycholysis (nail lifts up) may occur. Infection usually moves distal to proximal. Treat with oral itraconazole x 12 weeks or terbinafine if itraconazole fails

Question 12

What are the different locations of candidiasis?

Answer 12

Intertrigo-Axillae, under breasts, groin, intergluteal folds. Balantitis-Glans penis. Candidal folliculitis-Follicular pustules. Candidal paronychia-Nail folds. Thrush-Mouth and tongue. Diaper dermatitis

Question 13

What is the treatment of the different candidiasis infections?

Answer 13

Thrush-Nystatin, Clotrimazole. Cutaneous-powder (Nystatin), Clotrimazole (Lotrimin), ketoconazole. If failure of topical therapy then Oral fluconazole (diflucan)

Question 14

How do you diagnose and treat systemic candidiasis infections?

Answer 14

Blood cultures. May isolate organisms from urine or sputum. Isolated candida from blood cultures is considered a sign of serious disease. IV antifungal treatment such as fluconazole. Fundoscopic exam to excluded endopthalmitis

Question 15

What is the epidemiology of histoplasma capsulatum?

Answer 15

Found in the soil from bird or bat droppings. Endemic along major river valleys. Inhalation of the spores leads to lymphatogenous spread to other organs

Question 16

How is histoplasma capsulatum diagnosed?

Answer 16

Asymptomatic. Past infection may be noted by calcifications on routine xrays-Lungs,Spleen

Question 17

What is the epidemiology of coccidioidomycosis?

Answer 17

Infection occurs secondary to inhalation of molds from endemic areas. Southwestern US, Mexico, Central America, South America.

Question 18

What is the clinical presentation of coccidiodomycosis?

Answer 18

Pedal edema, Chest pain, Cough with blood tinged sputum, Fever, night sweats, Headache, Joint stiffness, Muscle pain, Anorexia, Erythema nodosum

Question 19

What happens in each body system if coccidiodomycosis disseminated?

Answer 19

Skin (erythema nodosum, verrucous skin lesions), Lungs (cavities, infiltrates, empyema, pleural effusion). Bones (lytic lesions). Soft tissues (abscesses). Lymph nodes (hilar and/or mediastinal lymphadenopathy, lymphadenitis and abscess formation). Meningitis

Question 20

What are characteristic lab results of coccididomycosis?

Answer 20

Leukocytosis, Eosinophilia, ELISA for IgM and IgG antibodies, Tissue or bone biopsy may reveal spores. Spinal fluid-Complement fixing antibodies, increased cell count, lymphocytosis, reduced glucose

Question 21

What is the treatment for coccidiomycosis?

Answer 21

Refer to ID specialist. Amphotericin B IV. Oral azoles. May require prolonged therapy. Surgical incision and drainage of abscess formation

Question 22

What is the epidemiology of cryptococcus?

Answer 22

caused by crytococcus neoformans. Yeast that is found in the soil and on dried pigeon poop. Most common cause of fungal meningitis. Rare in immunocompetent persons. 3 forms of infection: cutaneous, respiratory, meningeal

Question 23

What is the clinical presentation of crytococcus?

Answer 23

Pulmonary-Can lead to respiratory failure. CNS- HA, Confusion, Mental status changes, Cranial nerve abnormalities, Nausea, vomiting

Question 24

How is cryptococcus diagnosed?

Answer 24

Crytococcal antigen found in the infected organ and in the serum of AIDS patients. Respiratory- Sputum culture or pleural fluid. Lumbar puncture- Increased opening pressure, increased protein, decreased glucose. Positive India ink prep shows budding, encapsulated fungal cells.

Question 25

What is the treatment for cryptococcus?

Answer 25

Referral to ID specialist. Amphotericin B IV x 2 weeks. Followed by fluconazole x 8 weeks

Question 26

What is the epidemiology of aspergillosis?

Answer 26

caused by aspergillus fumigatus. Tissue invasion occurs with: Immunosuppression, Severe and prolonged neutropenia, High dose glucocorticoids

Question 27

What are clinical presentations of aspergillosis?

Answer 27

fever, chest pain, shortness of breath, cough, hemoptysis. CXR: single or multiple nodules with or without cavitation, patchy or segmental consolidation, peribronchial infiltrates.

Question 28

How is aspergillosis diagnosed?

Answer 28

high levels of IgE and IgG Aspergillus percipitins.
Galactomannan antigen from serum or bronchioalveolar lavage fluid. CT scan of the lungs-Ground glass infiltrates with a “halo sign” then development of a cavitary lesion

Question 29

What is allergic bronchopulmonary aspergillosis?

Answer 29

Preexisting asthma and worsening bronchospasm and pulmonary infiltrates. Waxing and waning course. May result in bronchiectasis and fibrotic lung disease. Treatment-Antifungals and steroids