A raised, encapsulated, fluid-filled lesion of any size.
What is a wheal?
A circumscribed area of edema of any size. A hive.
What is purpura?
Flat red-purple discoloration caused by RBC's lodged in the skin > 1cm. < 1cm are called petechiae.
What are the 3 key descriptors for diagnosing dermatological disorders?
Morphology, configuration, and distribution.
What is an excoriation?
A usually linear lesion, often covered with a crust. Any size.
What is a crust?
Raised lesions produced by dried serum and blood remnants. Any size. Ex. a scab.
What is a lichnification?
Skin thickening usually found over pruritic or friction areas. Ex. callus lichenification.
What are scales?
Raised superficial lesions that flake with ease. Ex. seborrhea.
What is an erosion?
Loss of epidermis. Ex. peeling.
What is an ulcer?
Loss of dermis and epidermis > 1cm.
What is a fissure?
A narrow linear crack into epidermis, exposing the dermis.
What is an annular distribution?
In a ring. Erythema migrans - Lyme dz.
What is a scattered distribution?
Generalized over the body without a specific pattern or distribution.
What is a confluent or coalescent distriution?
Multiple lesions blending together.
What is a clustered distribution?
Occuring in a group without pattern.
What is a linear distribution?
Occuring in streaks.
What is a reticular distribution?
Appearing in a net-like cluster. Erythema infectiosum.
What is a dermatomal distribution?
Limited to the boundaries of a single or multiple dermatomes. Shingles.
In dermatological assessment, if the pt is otherwise well, what is the likely diagnosis?
Likely the condition is limited to the skin w/ few/minor s/sx such as acne, rosacea, keratosis pilaris, and seborrheic dermatitis.
In dermatological assessment, if the pt is miserable but not sytemically ill, what is the likely diagnosis?
Pt will often be uncomfortable w/ itch, burning, pain, or the like. Examples incluse severe psoriasis, scabies, shingles.
In derm assessment, if the pt is systemically ill, what are the likely diagnoses?
When systemically ill, derm s/sx is likely manifestation of systemic dz i.e. varicella, transdermal necrosis, Stevens Johnson sundrome (erythema multiforme), Lyme dz.
Describe Chickenpox (Varicella).
2-3mm vesicles erupt initially on trunk and then appear on limbs 2-3 days later. Non-clustered lesions at a variety of stages of healing. Usually mildly to moderately ill, often quite miserable w/ itch w/ rare mortality.
2-3mm vesicles w/ generalized distribution without pattern. All lesions at the same stage at the same time. Severe systemic illness w/ about 35% mortality.
What is Actinic Keratosis?
Located mainly on sun exposed areas. Ranging in size from microscopic to severall cm in diameters. Red or brown, scaly, sometimes tender. Most common precancerous lesion. May be early squamous cell carcinoma. Lesions can remain unchanged, spontaneously resolve, or progress to invasive squamous cell carcinoma.
Tissue destruction options: Cryosurgery, laser resurfacing, chemical peel.
What is Basal Cell Carcinoma?
More common, on sun exposed areas, arises de novo as a papule or nodule w/ or w/o a central erosion. Pearly or waxy appearance, sometimes w/ telangiastica. Metastatic risk is low.
What is Squamous Cell Carcinoma?
Less common than BCC. Arises on sun exposed areas. Can arise from Aktinic Keratosis (AK) or de novo. Red, conical hard lesions w/ or w/o ulceration. Less distinct borders. Greater metastatic risk (3-7%). Also greater w/ lesion located on lip, oral cavity, or genitalia.
Malignant Melanoma A, B, C, D, E test.
C=Color not uniform
D=Diameter (usually > 6mm)
E=Evolving (new) lesion or change in a longstanding lesion, particularly in a nevus or other pigmented lesion. Sometimes Elevated.
> 2 features = 100% sensitivity, 98% specific.
Assessment and intervention includes biopsy, excision, w/ additional interventions based on results.
What is a tx for psoriasis vulgaris?
Vit D Cream.
What is tx for Herpes Zoster?
What is the tx for scabies?
What is the tx for verruca vulgaris?
What is the tx for tinea pedis?
What is the tx for rosacea?
Topical Metronidazole gel.
What is a tx for keratosis pilaris?
Where is the likely location for eczema?
Flexor surfaces, ie antecubital fossa.
What is the likely location of psoriasis vulgaris?
Extensor surfaces, ie anterior surface of knees.
Where are Actinic Keratosis located?
Where are scabies usually manifest?
Waist-band area, interdigital webs, wrist.
Where does pityriasis rosea manifest?
X-mas tree distribution on trunk after a herald patch on abdomen.
What is the sign of a brown recluse spider bite?
"Red, white, and blue." Central blistering with surrounding grey to purple discoloration at bite site. Surrounded by a ring of blanched skin surrounded by a large area of redness.