• Growths
• Rashes

• Based on complaint and pathological process
• Neoplastic change
• Epidermal, pigmented dermal process
• Raised

• Inflammatory response
• With or without epidermal component
• Flat

• Epidermis
• Dermis
• Subcutaneous Fat Tissue
• Skin Appendages

• Basal cell layer
• Stratum Spinosum
• Stratum Granulosum
• Stratum Corneum

• Provides the support and nutrition for the epidermis
• Contains the nerves and cutaneous appendages, blood vessels
• Thickness of 1-4 cm
• Nerves and fibers course through the dermis

• Collagen Fibers
• Elastic Fibers
• Ground Substance

• Insulates the body
• Cushions the deep tissue
• Serves as a food resource
• Located between the dermis and the fascia

• ALL located in the DERMIS

• Eccrine sweat glands
• Apocrine sweat glands
• Hair Follicles
• Sebaceous glands

• Most important appendage
• Helps regulate body temp by excreting sweat
• Total secretory capacity of 10L of sweat/day
• Important for the physically active and those living in the hot climates
• The sweat apparatus is similar to the kidney (glandular versus glomular)
• Excretion is followed by ductal re-absorption

• No useful function
• Responsible for body odor

• Vellus
• Terminal

• Produce an oily substance (sebum)
• Part of the pilosebaceous unit, therefore are found wherever hair follicles are
• Most prominent on the scalp and face
• Moderate on the trunk
• Size and secretory activity are under androgen control

• In newborns, they are large due to maternal hormones, but within months the glands shrink.  They enlarge again in pre-adolescence, reach full size at puberty when the gonadal androgens are produced

• Keeps the body in homeostasis
• Boundaries for body fluids
• Protects underlying tissues against injury
• Stops infection
• Tempurature regulation
• Synthesizes Vitamin D
• Prevents dehydration
• Prevents entry of microorganisms/noxious chemicals
• Screen and decrease radiation
• Provides friction surface for grip
• Provided caloric reservoir

Mechanisms are important in skin disease.

1. Immunology
2. Infection
3. Neoplasia
4. Genetics
5. Hormones
6. Nutrition
7. Psychology

• Pathologic organisms reach the skin internally and externally

• Barriers

--Physical

--Immunologic
--Microbial: Normal skin flora

• Staph Aureus
• Group A Beta hemolytic strep

3 DNA viral families common

• Popova (HPV)
• Pox (Molluscum Contagiosum, warts)
• HSV (Varicella is an exception, respiratory)

• Superficial (Tinea)
• Candida (Internal or External)
• Dermatophytes (Unique and common)

• Lime
• Syphillis

• Leprosy

• Skin CA

• Mutations
• Defect in DNA

• Approach does not differ markedly from an approach to any other patient
• History, a physical examination, possibly lab data
• Generate a differential diagnosis
• A modified history is suggested
• Pay special attention to the inspection portion of the PE (physical examination)
• Characterize each lesion
• Recall a pathophysiological process that may be responsible

• Dermatology is a visual specialty
• Skin lesions need to be looked FOR, not AT
• Remember the 2 broad categories of skin lesions:
  -growths and rashes

• History
• Physical
• Consider pathologic correlation
• Distribution of lesions
• Lab Tests
• Diagnosis
• Treatment

Preliminary: Chief complains and the HPI (history of past illness)

• First elicit the C.C.
• Then ask into the history of present illness
• Can be abbreviated by asking 3 simple questions

1. How long has it been there or noticed (onset and evolution)
2. Does it itch (symptoms)
3. How have you treated it (OTC treatment)

• Location/Duration
• Course Progression
• Systemic symptoms (joint pain, fever, fatigue)
• Aggravating or alleviating mechanisms
• Contacts

• Inspect all areas
• Use good light
• Start at the affected area and move out
• Wood's light
• Distribution
• Don't overlook the mouth, scalp and nails
• Palpation

Past Medical History

Review of Systems

Family History

Social History

Growths

• Epidermal
• Pigmented
• Dermal or Subcutaneous

• Resulting from hyperplasia of keratinocytes
• Most with scaling surfaces
• Scales result when the stratum corneum production exceeds shedding
• Hyperkeratosis
• Benign lesions often appear superficial
• Malignant lesions by definition have invaded the dermis and feel indurated (thickened)

• Result of a proliferative process in the dermis or adipose tissue
• Most often appear as nodules
• Definitive diagnosis is always by biopsy

1. Eczematous
2. Scaling
3. Vesicular
4. Papular
5. Pustular
6. Hypopigmented

• Primary
• Secondary
• Miscellaneous

• Macule
• Patch
• Papule
• Plaque
• Nodule
• Tumor
• Vesicle
• Bulla
• Pustule
• Wheal

• Crust
• Scale
• Pustule
• Purpura
• Erosion
• Fissue
• Ulcer
• Excoriation
• Atrophy
• Pigmentation
• Papilloma
• Cyst
• Lichenification

• Flat
• < 1 cm
• freckles, age spots, actinic lentigo, hemangioma, vitiligo

Papule

• Solid
• Slightly raised lesion
• < 1 cm
• psoriasis

• Fluid-filled
• < 1 cm

• Fluid-like
• > 1 cm

• Any size lesion filled with pus
• Herpes simplex virus, zoster, acne, pustular psoriasis,

• Mostly due to ruptures of vesicle
• NO BLEEDING
• canker sore

• deeper
• loss of epidermis and dermis
• can bleed
• almost always scarring
• common in diabetics

• Splitting linear crack of skin
• tinea pedis

• scabs
• dry residue from blood, pus
• impetigo contagiosa

• Drying, flaking of dead epidermis
• dandruff, severe dry skin, Ichthyosis Vulgaris

Linear erosions

scratches

• thinning of skin
• loss of adipose tissue
• Partial or complete wasting away of a part of the body

Purpura = larger

Petecchia = smaller (pinpoint)

Bleeding into the skin

• Generalized
• Photosensitive
• Intertiginous

Microscope

Cultures

Biopsy

Patch Tests

• If it scales, scrape it
• KOH for all undiagnosed lesions to rule out fungal
• Scabies (scrape with oil)

• Fungal, bacteria, viral
• Use the proper media
• Tissue cultures should be sent to the lab
• If it's a large lesion, send 2 specimens
• Swab exudate

• Nodules to rule out malignancy
• Usually done with a punch biopsy
• Excisional biopsy's also done
• Shave technique for very superficial lesions
• Speciman placed in formalin

• Used to ID allergens
• i.e. asthma