LECOM MMS Microbiology Lecture 12B- Derm. infections by Viruses and fungi

papillomavirus causes what disease

HPV

Characteristics of papillomavirus

naked, dsDNA virus

Transmission of papillomavirus

fomites, breaks in skin, sexual/direct contact (genital warts and cervical cancer), birth canal

cutaneous papilloma- clinical presentations and strains

common and plantar (1, 2, 4)

Flat (3 and 10)

Mucosal papillomavirus- clinical presentations and strains

condyloma acuminata (6 and 11)

cancer (16 and 18; >16=cancer)

common warts (HPV) are found on what body parts

hands or fingers, resolves on its own

Plantar warts (HPV) are found on what body parts

heels or balls of the feet

Appearance of common and plantar warts

white/gray grainy appearance

-Black dots/pinpoints

flat warts (HPV) appearance and location

flat/small bumps, skin-colored

most often on face, tops of hands, feet, arms, and legs

condyloma acuminatum (genital warts)

benign anogenital warts

condyloma acuminatum (genital warts) appearance

single or multiple, flat/dome/or cauliflower shaped

colors: white, skin-colored, red, or brown

HPV prevention (which strains are used for warts vs cervical cancer)

HPV vaccine: 6, 11= Warts

HPV vaccine: 16, 18, and higher= cervical cancer

Viral description of Measles

(-)ssRNA, enveloped

transmission of Measles

respiratory

very contagious -> most contagious virus (prior to covid)

1 antigenic variation

tropism of measles (how it infects)

endothelial, epithelial, and immune cells

measles clinical presentation

initial symptoms: High fever and CCC+P (Cough, Coryza, Conjunctivitis + phosphate), koplik spots

3-5 days after initial

-Maculopapular rash: begins below the ears and spreads downward

Complications of Measles

Pneumonia

Encephalitis (appears within days of rash, symptoms= seizures, confusion, ataxia, altered state of consciousness, vomiting)

Subacute sclerosing panencephalitis (SSPE)- muscle spasm (7-10 years after)

Prevention of Measles

MMR vaccine (measles, mumps, rubella)

live-attenuated

Rubella virus characteristics and transmission

(+) ssRNA, enveloped, icosahedral

respiratory droplets

very contagious (less than measles)

Rubella clinical presentation

low grade fever (101), enlarged lymph nodes, pink eye

Maculopapular pink rash- begins on forehead/face and spreads down

complications of Rubella

congenital rubella syndrome

-Can cross placenta (most problematic during first trimester)

-cataracts, intellectual disability, diabetes, deafness, decreased weight

-Can be fatal

Human Herpes Virus 6 (HHV-6) viral description and transmission

dsDNA, enveloped

ubiquitous virus

respiratory droplets

First phase of HHV-6

febrile phase

-Very high fever: 105

-irritability, respiratory symptoms, lymphadenopathy

Second phase of HHV-6

fever disappears, rash appears

Blanching maculopapular rash

-Starts at the Neck/trunk and spreads to face and extremities

HHV-6 complications and common population

febrile seizures due to high fever

2-3 years old (supportive care, resolves on its own)

Varicella Zoster virus (VZV) viral description and transmission

dsDNA, enveloped

respiratory droplets (also through direct contact)

Common population for VZV

mostly in children (5-9)

adolescents, adults, elderly

Where does VZV remain latent?

dorsal root ganglia

chickenpox clinical presentation (VZV) in children

fever and malaise

Maculopapular rash appears on torso and spreads (Several stages of papules at once)

chickenpox clinical presentation (VZV) in adults/adolescents

More severe: pneumonia and encephalitis

congenital VZV symptoms

cutaneous scars "dermatome" pattern

Limb abnormalities, ocular abnormalities, neurological abnormalities (hydrocephalitis)

VZV Zoster can cause

shingles- reactivation of VZV in dorsal root ganglion

What conditions can cause shingles

increasing age, immunocompromised, trauma

Clinical presentation of Shingles

before rash- pain, itching, paranesthesia

Rash: limited to dermatome -> unilateral and doesn't cross midline

-Fever and malaise

Postherpetic neuralgia (PHN):

- severe pain (several months after rash)

How to prevent shingles and chickenpox

vaccine

Parvovirus B19 viral characteristics and transmission

ssDNA, naked (smallest) and respiratory droplets

tropism of parvovirus B19

nasopharynx and erythroid progenitor cells (RBC precursors)

Common population of parvovirus B19

seen mostly in children and adults

Parvovirus B19 clinical presentation: Initial phase

infectious stage, can be asymptomatic, viremia (runny nose, headache, fever)

Parvovirus B19 clinical presentation: Immunologic (second) phase

not infectious

Malar rash on face: "Slapped-cheek"

spreads to torso and extremities days later

Complications with Parvovirus B19

Adults- Polyarthritis

Chronic hemolytic anemia patients- transient aplastic crisis

Fetus- hydrops fetalis

- Anemia, edema in fetus -> can lead to spontaneous abortion

Coxsackie A viral description and transmission

(+) ssRNA, Naked, icosahedral

fecal-oral

Coxsackle A causes what disease

Hand, Foot, and Mouth Disease

Hand, foot, and mouth disease clinical presentation

fever: 101

oral rash: Tongue and buccal mucosa

Macule -> Vesicle -> Ulcer

Hand and foot rash:

Maculopapular or vesicular rash (palms and soles)

- can be on buttocks, legs, and arms

Herpangina is caused by

Coxsackie virus A

Clinical presentation of Herpangina

high fever: 103

sore throat, vomiting, irritable/fussiness, vesicular-ulcerated lesions (soft palate and uvula)

Malassezia furfur lab characteristics

Olive oil test- lipophilic

KOH prep- kills all cells except fungi

Wood lamp (like tinea capitis)

geographical location and at risk population of Malassezia furfur

tropics

adolescents and young adults

M. furfur morphology/Microscopy

"Spaghetti and meatballs"

dimorphic

lipophilic (Olive oil test)

M. furfur causes what disease

Pityriasis versicolor

Pityriasis versicolor clinical presentation

lesions:

-Trunk, arms, shoulder, face, and neck

irregular and well-demarcated (raised and scaly)

Melanin production (hypo vs hyper pigmentation)

Other infections caused by Pityriasis versicolor

folliculitis

catheter related fungemia:

-Neonates

fever, respiratory distress, and thrombocytopenia

Microsporum (ring-worm) morphology/microscopy

spindle-shaped

Microsporum lab characteristics

Physical examination

KOH preparation

Sabouraud dextrose agar

Dermatophyte test medium:

-Modified Sabouraud dextrose agar

-turns red if dermatophyte (turns yellow if not one)

What disease is caused by microsporum

Tineas Ring-shaped rash

Tineas clinical presentation

Hair loss, ring-shaped rash, pruritis, and dry/scaling skin

Candida albicans morphology and predisposing factors

yeast, gram positive (opportunistic infections)

factors:

1. Age

2. Climate

3. Immunocompromised

4. Obesity

Candida albicans microscopy/diagnostics

germ tube, gram positive, Sabouraud dextrose agar, and dimorphic

Candida albicans leads to what disease

Onychomycosis intertrigo- "diaper rash"

Onychomycosis intertrigo clinical presentation

At risk: obese and pregnant individuals

rash grows in skin folds -> moist, red patches, pruritis

Sporothrix schneckii geographical location and transmission

North/South America

Traumatic inoculations:

-Rose bush, soil

Sporothrix schneckii morphology/microscopy

"Daisy petal"

cigar-shaped

Splendore-Hoepppli (asteroid body)

dimorphic fungi

what disease is caused by Sporothrix schneckii

Lymphocutaneous sporotrichosis

Lymphocutaneous sporotrichosis clinical presentation

site of inoculation: nodule appears -> line up the arm (from site of infection)

Ulcerates

2 weeks later: Lymphatic nodules appear

Lab characteristics for Sporothrix schneckii: Culture

Sabouraud dextrose agar:

-Growth at room temperature

White -> brown/tan/black colonies