Lectures 1-3 Flashcards
Are the red scaling patches of atopic dermatitis well defined or ill defined?
Ill defined
What are some long term complications from SJS/TEN?
Scarring/contracture of skin
Vision loss/eye problems
Pulmonary complications
What is onychomycosis?
Infection of the nail by:
Fungus
Yeast
Non-dermatophyte molds
What color is tinea versicolor
Variety of colors!
Hypopigmented
Hyperpigmented
Erythematous
Clinical manifestation of melanoma?
Most de novo, with some arising from pre-existing nevus
Usually asymptomatic
Pigmented papule, plaque or nodule
DDx for BCC?
Sebaceous Hyperplasia- enlarged oil gland with central clearing.
Fibrous Papule-benign angiofibroma. Skin colored/pink papule on nose. No telangiectasia and lacks pearly texture.
On infants, is atopic dermatitis on the flexor surfaces or extensor surfaces?
Starts on extensor surfaces then moves to flexor surfaces once they start crawling/walking
Burning stinging pain on hands is associated with which skin condition
Irritant contact dermatitis
Presentation of proximal subungual onychomycosis
Starts near cuticle and progresses out
Uncommon
Usually seen in VERY immunocompromised ppl (like AIDS)
Is sweat isotonic or hypotonic?
It starts isotonic with plasma, but due to electrolyte reabsorption in duct, it becomes hypotonic
What is intertrigo
Any inflammatory condition of two closely opposed (intertriginous) skin surfaces
-often due to candida species
What might a patient report before a drug eruption?
A prodrome involving fever, malaise, flu-like symptoms
Which is more common, distal or proximal subungual onychomycosis?
Distal, by far
Why does tylenol get blamed for SJS/TEN?
Because people take tylenol for the prodrome they feel for 1-3 days before rash erupts and they blame it on that.
Which layer of epidermis has keratinization?
Stratum granulosum
Some cancers start here
Tx of nondermatophyte onychomycosis
Oral itraconazole
6wks for fingernails
12 wks for toes
What skin condition is associated with occupations like bartenders, hairdressers, cleaning ladies?
Irritant contact dermatitis
What does SJS/TEN look like before skin starts sloughing off?
TENDER red and purple macules with blisters
Clinical presentation of tinea corporis
Pruritic, annular, erythematous plaque
(Itchy, red, round plaque)
Central clearing **
RAISED advancing border (touch it)
What does a drug eruption look like
Erythematous macules and papules
Measles-like
Diagnosis of tinea versicolor
KOH prep Woods lamp (1/3 of them glow yellow-green) not very useful
What is Leser-Trelat sign?
Sudden onset of multiple SKs with inflammatory base
+skin tags
+acanthosis nigricans
=possible association with GI and lung cancers
What is the dominant symptom of allergic contact dermatitis?
Itch
Difference between acute and chronic tinea pedis?
Acute-self limited, intermittent, recurrent infection. Itchy painful blisters following sweating with 2* staph infections common.
Chronic- slowly progressive infx that persists indefinitely. Interdigital fissures and erosions/scales between toes (especially 3rd and 4th)
Clinical presentation of tinea capitis?
Scaly patches with hair loss
Hair loss with black dots
Widespread scaling w. Minimal hair loss
Kerion (boggy, edematous, painful plaque)
Favus (multiple cup shaped yellow crusts aka scutula)
Who is at risk for scabies infection
EVERYONE
Most common cell in epidermis?
Keratinocytes
Risk factors for Malignant melanoma?
Genetic predispostion Prolonged UV exposure Fair skin/hair/eyes Immunosuppressed 6+ atypical nevi 26+ regular nevi
How long after taking a drug will a drug eruption occur
5-14 days
What are 5 common drugs that can cause drug eruptions?
Penicillins Cephalosporins Sulfonamides Carbamazepine Phenytoin
What types of cells are in the hypodermis (subcutis)
Fibroblasts, adipose, and macrophages
What is distinctly different about SJS/TEN vs drug hypersensitivity syndrome?
SJS/TEN involves mucous membranes
Where is it NOT OK to use high potency steroids?
Face
Skin folds
Genitalia
Risk factors for tinea versicolor
Tropical climate
Adolescents
Hyperhidrosis
Immunosuppression
What are the 2 types of severe cutaneous adverse reactions?
- drug hypersensitivity syndrome
- Stevens-Johnson/Toxic Epidermal Necrolysis
Where does tinea cruris begin?
Inguinal fold
What area is usually spared by atopic dermatitis in children?
DIAPER AREA
Treatment for solar lentigo?
No treatment required
Treatment of tinea versicolor
Topical: Clotrimazole x 2 weeks Selenium sulfide x 1 week (shampoo, lotion, foam) Zinc pyrithione shampoo x 2 weeks Systemic: Itraconazole
Appearance of tinea versicolor
Macules, patches, plaques on trunk & arms
Often have a fine scale
Can coalesce into a big patch
Might itch
What is the gold standard treatment for atopic dermatitis?
Petroleum (Vaseline) applied twice a day and right after bathing
Goal is to hydrate the skin with emollients
What are important features (not essential) of atopic dermatitis that would add support to your diagnosis?
Atopy (predisposition to developing allergic hypersensitivity rxns)
Early age of onset
Xerosis (dry skin)
What is a solar lentigo
“Age spot”
Flat, brown macule
Often in groups
Well circumscribed
What does nummular eczema look like?
Coin shaped red lesions
Features of nodular melanoma
AGGRESSIVE
Nodule is INFLAMED AND FRIABLE
Rapid vertical growth
Who should get systemic treatment for tinea corporis
- immunocompromised
- failed topical tx
- tinea corporis gladiatorum (no participation for 10-15 days) (athletes are eager to get back)
What does irritant contact dermatitis look like?
Dry, red chapped skin with fissuring
Keratosis Pilaris is a disorder of what
Keratinization
Keratinocytes don’t slough off right
Associated signs of tinea capitis?
- Swollen cervical nodes
- Dermatophytid rxn-eczema like rxn after starting tx
- Erythema nodosum- leg lesions (rare)
From where does BCC arise?
Basal layer of epidermis (least concerning)
What will happen if you treat tinea corporis with a steroid?
It gets worse (mojocchi’s granuloma)
+you waste money
What is a positive Nikolsky sign?
Skin blisters and separates as a result of gentle mechanical pressure on the skin
Features of superficial spreading melanoma?
Most common subtype (70%) Confined to epidermis Grows out not up Younger people Men:back Women: back and legs
Where is atopic dermatitis usually found in infants?
CHEEKS
Trunk
Extremities
What skin condition is an example of a DELAYED hypersensitivity reaction
Allergic contact dermatitis
How is SJS/TEN diagnosed?
Clinically initially: blisters in mouth, been feeling feverish, has the rash…
Then,
biopsy looking for 2* infections
Culture blood, wound, mucosal lesions
Diagnosis of actinic keratoses?
Typically based on appearance and texture.
If over 1cm, rapidly growing, ulcerated or painful, you should biopsy.
If over 6mm, consider SCC in situ.
Clinical presentation of tinea cruris
- WELL MARGINATED, scaly round plaque with a RAISED border
- extends from inguinal fold to inner thigh
- scrotum typically spared
Presentation of white superficial onychomycosis
- starts w dull white spots on nail
- spreads OUT over entire nail
- soft lesions that can be scraped for sampling
Poison ivy, oak, and sumac contain what oil that causes allergic contact dermatitis 12-24hrs later?
Urushiol oil
Is irritant contact dermatitis an immune response?
No
Most common type of skin cancer?
Basal cell carcinoma
What effect does more melanin have on skin tone and vitamin D production?
Darker skin tone
Difficulty synthesizing vitamin d
Where is the Basement Membrane Zone
Between the epidermis and dermis.
It is a barrier for malignant cells.
What distinguishes SJS from TEN?
SJS is less than 10% surface area
TEN is more than 30% surface area
(SJS/TEN overlap if 10-30%)
Where is dyshidrotic eczema found
Hands, sides of fingers, palms/soles
Treatment of Tinea capitis
Systemic anti fungal therapy- Griseofulvin x 6-12 weeks
Tx of choice for Microsporum genus or EMPIRIC tx
Treatment of tinea pedis
Clotrimazole x 4 wks (topical)
itraconazole (oral) for chronic/extensive disease.
+Burow’s wet dressings for vesiculation/maceration 20 min 2-3x/day
+foot powder/better shoes etc
(SIMILAR to tinea corporis but typically requires longer tx bc its stubborn)
4 layers of epidermis
Stratum corneum Stratum lucidum *palms/soles Stratum granulosum Stratum spinosum Stratum basale
“Come lets get sun burned”
Dermatitis and Eczema are used interchangeably, but dermatitis is most often used to describe ____ causes
Exogenous.
Ex: irritant contact dermatitis, allergic contact dermatitis, seborrheic dermatitis etc