Basic Derm 1 Flashcards
Basic history for a rash?
WHISPer Fart in MECCa
- Where is rash and where did it start?
- How long? (Acute/subacute/chronic)
- Itchy? Severity of itch
- Supplementary: contacts, meds, new clothes or exposures, PHX (rash, asthma, eczema), FHX
Clinical questions you’re trying to answer:
- Is this a drug rash?
- Has the rash been modified by treatment?
- Any contacts with a similar rash?
What is cellulitis?
Acute spreading skin infection
Indistinct borders
Mainly involves dermis and subcutaneous tissue
Cause of cellulitis?
Mostly Strep pyogenes
S. Aureus secondly, can be more severe
Break in skin
Principles of Management of cellulitis?
Rest in bed and limb elevation at all times Basic analgesia Wound cleansing Dressing with non stick saline dressings Antibiotics
Antibiotics for cellulitis?
Empiric or known S. aureus:
Flu/dicloxicillin
days
Penicillin allergy: Keflex
Confirmed S. pyogenes: phenoxymethylpenicillin
All doses are 500mg q6h PO 7-10 days
What is erysipelas?
Form of superficial cellulitis
Raised, sharply demarcated borders from uninvolved skin
Lymphatic involvement
Causes and management is as per cellulitis
What is impetigo?
Superficial, contagious, blistering infection of skin caused by S. aureus / S. pyogenes. Can be bullous or vesiculopustular.
Causes of impetigo?
S. Aureus
S. Pyogenes
Skin trauma, but 30% cases (bullous) occurs on intact skin
Distinguish between bullous and non bullous impetigo.
Bullae: fluid filled lesions >0.5cm diameter
Vesicles: fluid filled lesions <0.5cm diameter
Non bullous (vesiculopustular) is more common (70% cases) and occurs at skin trauma. Can be caused by either or both S aureus and S pyogenes.
Bullous is less common and occurs on intact skin.
Principles of managing impetigo?
- Topic antiseptic and cleansing to remove crusts
- Topical antibiotic
- Minimise recurrence and transmission
- Antibiotics for extensive lesions or systemic features
Prescribe your topical therapy for impetigo.
Antibacterial soap (saline chlorhexidine or povidone iodine) cleansing to gently remove crusts.
Follow with 2% Mupirocin (bactroban) small amount TDS x 10 days
Describe measures to reduce recurrence and transmission of impetigo.
Daily bath with Oilatum Plus bath oil for 2 weeks
Hot water wash for clothes, towel and linen for 2-4 weeks
Regular hand washing
Exclude from childcare settings until sores fully healed
A child with impetigo has extensive lesions and shows systemic features. What antibiotics will you use?
Fluclox/dicloxicillin 6.25mg/kg up to 250mg q6h PO x 10 days
If allergic then Keflex (same dose)
Basic examination for lumps and bumps?
Look Feel Move Measure Auscultate Transilluminate
Approach to describing lumps and bumps?
A number with poor eyesight is eating shapes - he changes size then falls into another position onto a stony hard rock, which is a cyst. It turns out to be mobile, which goes to buy a surface with lots of special features.
Ie
Number, site, shape, position, consistency (soft v hard), solid v cystic, mobility, surface, special features
What anatomical questions are you trying to answer when examining lumps and bumps?
Skin / SC tissue / muscle / tendon or joint / bone
In Skin: moves with skin
In SC tissue: skin moves over lump, slipping sign
In muscle: movable when muscle relaxed, limited movement when contracted
In tendon/joint: movement of these may change mobility or shape
In bone: immobile, best outlined when muscle relaxed
Define an epidermoid cyst
Aka sebaceous cyst
Benign cyst arising from ectodermal tissue
Results from proliferation of epidermal cells in circumscribed space of the dermis
Clinical features of an epidermoid cyst?
Fixed to skin but not other structures Regular lump, usually round Mainly scalp, also face, neck, trunk, scrotum Soft to firm Cystic Moves with skin Special features: - usually fluctuant with sebaceous material - tends to get inflamed - +/- central punctum with keratin
Management options for epidermoid cyst?
If before puberty: consider polyposis coli
Can leave alone if small and not bothersome
Surgical:
Method 1: incision into cyst
Method 2: incision over cyst and blunt dissection
Method 3: standard dissection
Infected cysts: incise and drain purulent material. When inflammation completely resolved remove cyst by method 1 or 3
What is seborrhoeic keratosis?
Common benign skin tumour, usually multiple
Most commonly on torso, face, but can be found anywhere
Age > 40 (number + pigmentation tends to increase)
What age does seborrhoeic keratosis tend to present?
Age >40
80-100% people over age 50 are affected
Clinical features of seborrhoeic keratosis?
Pt age >40 Number: Multiple Site: Sits on skin, torso or head but can be anywhere Shape: "Sultana pressed into skin", well defined border Size: <1cm diameter usually Surface: Pitted Special features: get-brown to black Usually asymptomatic
What is solar Lentigo?
Aka actinic keratoses, sunspots
Intraepidermal keratinocytic dysplasia with potential for malignant change (especially on ears)
Reddened scaly hyperkeratotic thickenings occurring on light exposed areas
Clinical features of solar lentigo?
Site: Sun exposed fair skin (face, ears, scalp if balding, forearms, dorsum of hands)
Size: Variable (2-20mm diameter)
Surface: Dry and rough, adherent scale
Special features:
Usually asymptomatic, might have discomfort on rubbing with towel
Scale can separate to leave oozing surface
Small proportion will undergo malignant change
You are suspecting an infectious cause of your patients rash. What are the common infectious conditions of the skin?
An IMP in a CELL finds a TIN CAN full of tomatoes - he has a TOMATO-FIGHT with the guard who PITYs him and gives him ROSES. He says PHEW.
Bacterial: Impetigo, cellulitis
Fungal: Tinea, Candidiasis, Dermatophytes, Pityriasis versicolor
Viral: Pityriasis rosacea, HSV/HZV, Exanthema, Warts
Definition of Dermatophytes?
Dermatophytes are fungal organisms that require keratin for growth.
They cause superficial infections of hair, skin and nails.
Spread by direct contact from people, animal, soils, clothes, utensils and furniture
Types of Dermatophyte infections?
By site: hair, hair follicles, perifollicular skin, keritanized epidermal skin, nail apparatus
By species: Microsporum, Trichophyton, Epidermophyton
Definition of Tinea Cruris?
Tinea cruris is a common dermatophyte infection of the groin area caused by Tinea infection
Usually young men esp. athletes
Transmitted by towels and objects in locker rooms, saunas ad communal showers