Infections & Infestations Flashcards
Describe the progression of HSV? [3]
1st exposure causes the first clinical episode or goes straight to latency.
Lies latent in your DRG (dorsal root ganglion)
New episodes occur due to certain stimuli
What can cause a flare up of HSV? [5]
- Trauma
- Menstruation
- Sunlight
- Fever
- Stress
So if a patient presents with small closely grouped vesicles/pustules that come and go in the same place?
Herpes simplex virus
Tends to return to the same spot as the first exposure e.g. hands/genital/mouth
How do we treat HSV?
Aciclovir
What patients suffer particularly severe HSV infections? [2]
Immunocompromised or atopic patients
How does Herpes Zoster Virus appear?
Closely grouped vesicles in a dermatomal distribution
What conditions are caused by HZV? [2]
Chickenpox on primary exposure
Shingles later
Complications of HZV [2]
Extensive Scarring and Post-herpetic Neuralgia
If a patient tells you they had a small number of papules/vesicles on their hands and after 6 weeks broke out in itchy excoriations and pustules on their chest what do you think they have?
SCABIES!! Delayed type IV hypersensitivity to sarcoptes scapei
Female mite digs a burrow and lays eggs which hatch as larvae.
How are Scabies transmitted? [2]
Person to person.
Its slow, you have to hold someones body for around a minute for the mites to pass over. (loved ones that share beds)
What can you look for to confirm scabies? [3]
- Papules, vesicles, pustules and nodules affecting
- Fingers, wrist flexures, axillae, abdomen, buttocks and groins
- Characteristic wavy red or grey line where burrowed
How do you treat scabies? [3]
- Permethrin 5% cream
- Patient has to cover their whole body in it, wash off after 24h, repeat in 1 week - Oral ivermectin if severe
Ensure you treat all their contacts simultaneously (household) to prevent re-infection
What virus causes warts?
Incubation period?
Natural course?
Human Papilloma Virus (HPV)
has a 4 month incubation period
Usually regresses within months-2y
What are the types of Warts? [4]
Common
Plantar
Genital
Other - Plane/filiform/mosaic
How do you treat warts? [4]
- Largely let them regress themselves, intervene only if symptomatic
- Chemical paints e.g. salicylic acid
- Cryotherapy 3-4w weekly
- Imiquimod (genital warts)
What are the main causative organisms for bacterial skin infections? [2]
Name 2 bacterial skin infections [2]
Staph Aureus
Streptococci
Erysipelas
Cellulitis
How do we treat bacterial infections? [2]
Antibiotics - IV for Erysipelas
Drain pus from a boil
Whats the most common fungal infection and how do you get it?
Candida Yeast
Wet, unclean areas like under breasts. nails or between fingers get infected if poor hygiene
How does candida present and how do we get ris of it? [2]
Erythema rash with satellite pustules
Oral or topical antifungals (e.g. fluconazole)
What infections can dermatophyte fungi cause? [4]
Tinea Pedia (Athlete’s Foot)
Tinea Corpuris
Tinea Cruris (akak Tinea Incognito)
Tinea Barbea
Describe presentation of the following Tinea infections: Tinea corpororis Tinea crusis Tinea pedis Tinea manuum Tinea capitis Onychomycosis Tinea incognito Pirtyriasis versicolour
- Tinea corporis: itchy annular lesions of trunk and limbs with clearly defined raised and scaly edge
- Tinea crusis: itchy annual lesions of groin and natal cleft with clearly defined raised and scaly edge
- Tinea pedis (athlete’s foot): moist scaling and fissuring of toe webs, spreading to sole and dorsal aspect of foot, white flaky skin
- Tinea manuum: scaly and drying of palmar creases
- Tinea capitis: patches of broken hair, scaling and inflammation
- Onychomycosis: yellow discolouration, thickened and crumbly nail (usually due to Trichophyton rubum (dermatophyte))
- Tinea incognito: inappropriate treatment of tinea with topical or systemic corticosteroids causes ill-defined and less scaly lesions
- Pityriasis versicolour: pale brown patches on upper trunk that fail to tan on sun exposure
How do we test for Tinea infection? [1]
Skin scrape from the edge of the scaly rings for a fungal culture
What is Kerion?
A fungal scalp infection, mainly in kids whos scalps dont make much sebum (grease). Fungal causing abscess.
How do we test for kerion?
Hair sample from affected area for a fungal culture
What is erysipelas
Acute superficial infection of dermis and upper subcutaneous tissue
