Skin! Flashcards
Impetigo
bacterial infection of the epidermis
Cellulitis
infection of the dermis
folliculitis
bacterial infection of appendages
What does stratum corneum do?
prevent water loss, chemical entry
What does dermis do?
It is tough, repels physical insults
What does subcutaneous fat do?
protects underlying structures from injury
Bacterial infections of skin
Impetigo
Folliculitis
Viral infections of skin
Herpesvirus
molluschi contagiosi
Verruca vulgaris
Fungal infections of skin
Tinea versicolor
Tinea corporis
Deep fungal infection
Infestation
Scabies
Myiasis
Normal skin flora
Aerobic cocci, aerobic and anaerobic coryneform bacteria, gram negative bacteria, yeast
Infectious panniculitis/fascitis
bacterial infection of fat layer/fascia
Most cutaneous infections are caused by
Staph aureus
Destruction of follicle wall, PMNs. What it is?
Folliculitis- treat with antibacterial soap, topical or systemic antibiotics
papovavirus
warts
DNA viruses infect
keratinocytes
RNA viruses infect
CD4 helper T cells
Viral infections of the epidermis
Molluschi contagiosa
Herpesvirus
Verruca
What is an appendage viral infection of skin?
Folliculitis from herpes virus
A positive interpretation of the Tzanck smear requires
identification of multi-nucleated keratinocytes
-peripheral margination of chromatin (ground glass appearance)
If you have a negative reading of a Tzanck smear, what should you do?
It is probably still herpes. Scrape again. It if pretty specific and sensitive
How does Herpes Varicella Zoster happen?
reactivation of varicella zoster virus (chicken pox) from the dorsal root ganglion. Travels down nerve into skin. Usually in immunosuppressed and old people. Usually unilateral in one dermatome
Double stranded DNA viruses:
Herpes simplex 1 and 2
Varicella (chicken pox, herpes)
Cytomegalo virus
Epstein-Barr (infectious mono)
Herpetic whitlow
Herpes in your digits
Eczema herpeticum
life threatening infection of a pre-existing skin rash, usually atopic dermatitis
Herpes Zoster
Shingles or chickenpox
Where does oral herpes occur?
keratinized tissue (palate, gingiva, tongue)
Oral Hairy Leukoplakia
Epstein-Barr virus (EBV)
Common in HIV patients, immunosuppressed, smokers
Usually don’t have to treat. Or systemic antivirals, (acyclovir and brothers)
Henderson-patterson bodies
molluscum bodies. (Pox virus causes red inclusions). Little kids and STD. Cause umbellicated spots
What are the signs of HPV
Thick granular cell layer with koilocytes
What are the HPVs of Verruca vulgaris
HPV 1,2,4, 27, 57, 63
What are the HPVs of Verruca Plantaris?
HPV 1,2,4,27,57
What are the HPVs of Verruca plana
HPV 3,10,28,41
What are the HPVs of genital warts or condyloma?
HPV 6,11
Fungal infections of the epidermis/stratum corneum
Tinea versicolor
Dermatophytosis
If a rash is scaly,
do a KOH preparation to make sure it isn’t fungus (if it is, steroids will make it worse)
What causes Tinea Versicolor
Pityrosporum orbiculare
Dermatophyte infection
Can only survive on dead keratin or hair and nails (aka ringworm)
What do you see with paracoccidoidomycosis?
Mariner’s wheel
What is the key risk factor for deep fungal infections?
Neutropenia (immunosuppression is big too)
Common fungal deep infections
Candidiasis
Aspergillosis
(These can be life threatening)
Where does a scabies mite lay eggs?
In the stratum corneum (circle of hebra: wrists, hands, genital region, axilla)
Botflies are an example of
Myiasis
