Hair, Skin & Nails – Advanced Health Assessment Bullet Notes

Objectives

Conduct complete dermatologic history
Demonstrate full‐body skin, hair, nail examination techniques
Contrast normal vs. age-, pregnancy-, and disease-related variations
Detect deviations from expected findings and relate to common pathologies
Formulate initial differential diagnoses (DDx) for skin problems
Recognize dermatologic red flags (emergent or systemic disease indicators)
Accurately document history, exam, DDx in SOAP format

Inclusive Dermatology – Equity Highlight

2024 NEJM “Efforts toward Equity” article profiles the Inclusive Dermatology Atlas (UNM)
• Open, online photo bank covering Fitzpatrick skin types I–VI
• Goal = improve diagnostic accuracy & reduce disparities among patients of color
• Images de-identified and consented; created 2022 (UNM + East Carolina Univ.)
• Addresses bias created by traditionally light-skin–dominant teaching images

Quick Anatomy & Physiology Review

Skin = largest organ; layers: Epidermis → Dermis → Subcutaneous tissue
Functions
• Barrier to microbes, injury, fluid loss
• Thermoregulation, BP modulation (vasomotor, sweat)
• Sensory perception & emotional expression
• Vitamin D synthesis; immune surveillance & wound repair
• Waste excretion (sweat, urea, lactic acid)
Appendix structures
• Hair follicles, sebaceous glands, eccrine & apocrine sweat glands, nails

Epidermis (thin, avascular)

Stratum basale (germinativum): mitosis, melanocytes, Merkel cells
Stratum spinosum: keratinocytes
Stratum granulosum: lamellar granules
Stratum lucidum (palms/soles only)
Stratum corneum: dead, keratin-filled cells

Dermis

Papillary layer → dermal papillae; Reticular layer → collagen/elastic fibers
Contains vessels, nerves, Meissner & Pacinian corpuscles, hair follicles, glands

Subcutaneous tissue

Adipose, larger vessels, insulates, cushions, energy storage

Hair Overview

Derived from epidermal invagination into dermis
Pigment supplied by follicular melanocytes
Types: Vellus (fine), Terminal (coarse, pigmented)
Pilosebaceous unit = hair follicle + sebaceous gland + arrector pili muscle

Sweat & Sebaceous Glands

Eccrine
• Widely distributed; abundant on palms, soles, forehead
• Simple coiled tubular gland; duct opens directly to skin surface; watery sweat
Apocrine
• Axillae, anogenital regions; larger; ducts empty into hair follicles
• Sweat contains fatty acids & proteins → bacterial decomposition → body odor
Sebaceous glands
• Holocrine exocrine glands, secrete sebum into hair follicle; lubricates skin/hair

Nails

Epidermal cells transformed into hard keratin plates; vascular nail bed beneath
Key landmarks: Nail root, plate, lunula, eponychium (cuticle), hyponychium, folds

Lifespan Variations

Infants

Smooth skin, limited subcutaneous fat, no apocrine function
Vernix caseosa at birth; desquamation of stratum corneum
Lanugo sheds by day 10–14; eccrine glands functional ≈1 month

Adolescents

Surge of androgens → apocrine activation, seborrhea, acne, terminal hair axillae/pubic, male facial hair

Pregnancy

↑ Blood flow, eccrine & sebaceous activity, subdermal fat
90 % hyperpigmentation: face (melasma), nipples, areolae, linea nigra, axillae, vulva
Striae gravidarum common

Older Adults

↓ Sebaceous & sweat gland activity (xerosis)
Thinning epidermis, ↓ collagen & elasticity, ↓ subcutaneous fat
Graying hair (fewer melanocytes), androgenic alopecia (terminal → vellus)
↑ Facial hair in women; ↓ axillary/pubic hair; thicker nares/ear hair in men
Slower nail growth, ridging/thickening

Dermatologic History Framework

VINDICATE S/P Etiology Mnemonic

Vascular, Inflammatory/Infection, Neoplastic, Degenerative/Deficiency, Idiopathic/Intoxication, Congenital, Autoimmune/Allergic, Traumatic, Endocrine, Social/Psychological

Chief Complaints

“Rash”, “hair loss”, “weird growth”, pruritus, pain, burning, bleeding, color change

OLDECARTS – HPI Elements

Onset, Location, Duration, Evolution, Characteristics, Aggravating/Associated, Relieving, Timing, Severity + Patient perception of cause

Anatomic Clues (“Location, location, location!”)

Scalp: seborrheic dermatitis, tinea capitis
Face: melasma, rosacea, acne, impetigo …
Torso: pityriasis rosea, tinea versicolor, eczema …
Hands/palms; soles; genitals – list specific conditions (secondary syphilis, scabies, etc.)
Pattern terms: Fixed, Evanescent, Migratory

Past Medical Hx

Prior skin/hair/nail issues; severe sunburns; systemic diseases (autoimmune, endocrine, hepatic, renal, vascular, psych)
Recent infections (HSV), malnutrition, trauma, NEW MEDICATIONS, allergies

Systemic Disease → Cutaneous Manifestations (selected)

Diabetes → acanthosis nigricans, diabetic dermopathy, infections…
Hyper- vs. Hypothyroid skin traits
Cushing: striae, atrophy; Cirrhosis: spider angiomas, palmar erythema …

Family, Social, Skin-care, ROS highlights

Atopy, autoimmune dz, skin cancer, hair loss genetics
Substance use, stress/sleep, occupation, sun exposure, travel, pets, sexual hx
Cleansers, cosmetics, diapers, alternative remedies, product changes

Physical Examination of the Integument

Equipment

Ruler, adequate lighting, Wood’s lamp (fluorescence patterns), magnifier, dermatoscope, gloves, tongue blades, scalpel for scrapings

Preparation

Comfortable room temp, full exposure & draping, inspect mucosa, folds, back, buttocks, interdigital spaces; infection control

Techniques

Inspection → color, symmetry, thickness, hygiene, lesions (morphology, location, color, borders, texture)
Palpation → moisture, temperature, turgor, mobility, induration, tenderness, blanching
Olfactory (e.g., pseudomonas odor), Skin scrapings for KOH/Gram/PCR

Special Palpation Signs

Blanching (erythema vs. purpura), Nikolsky (
• $+$ = epidermal separation)
Dermatographism, Auspitz’s sign, Koebner phenomenon

Lesion Description System (memorize!)

Primary morphology (macule, papule, vesicle, pustule, plaque, nodule, wheal, cyst, bulla, burrow, telangiectasia)
Secondary morphology (scale, crust, erosion, ulcer, fissure, scar, keloid, excoriation, lichenification)
Configuration/shape (round, annular, linear, zosteriform, target, serpiginous, cluster, confluent, reticular, satellite, lacy, morbilliform)
Location & distribution (localized, regional, generalized, photodistributed, acral, dermatomal, flexural, extensor, follicular, symmetric…)
Borders (well-demarcated, poorly-defined, active/advancing, collarette)
Color (red, violaceous, brown, black, hypopigmented, dusky, pearly…)
Size (measure objectively; compare to coin if no ruler)
Texture/other (umbilicated, indurated, waxy, fluctuant, mobile, tender, warm)

Practice Documentation Examples (condensed)

1 cm pink pearly papule with telangiectasia ↓ L infra-orbital rim → DDx BCC
Zosteriform cluster of vesicles on erythematous base along L T5 dermatome → Herpes zoster
Hyperpigmented velvety poorly-demarcated plaque entire posterior neck + 3–4 mm soft papules → Acanthosis nigricans + acrochordons
Symmetric salmon-colored scaly plaques R anterior chest; nail pitting → Psoriasis
5×3 cm dark-brown waxy “stuck-on” oval plaque upper L scapula → Seborrheic keratosis

Nevi & Skin Cancer

Common Nevi

Junctional, compound, dermal

Atypical Nevi

Larger, irregular borders/color; melanoma precursor risk

ABCDE Warning Signs

Asymmetry, Border irregularity, Color variation, Diameter > $6\,\text{mm}$ , Evolution

Fitzpatrick Phototypes

I (always burns) → VI (never burns); everyone requires sun protection

Malignant Melanoma (MM)

Pigmented papule/plaque, black/brown, irregular border/color, >6 mm, evolving
Types: Superficial spreading (most common), Nodular, Lentigo maligna, Acral lentiginous
Risk factors: personal/family hx, atypical nevi, >40 y, male, fair skin, tanning beds, immunosuppression, prior NMSC

Basal Cell Carcinoma (BCC)

Most common cancer; sun-exposed sites; pearly, telangiectatic papule, may ulcerate (“rodent ulcer”)
Subtypes: Nodular ≈80 %, superficial, infiltrative, pigmented

Cutaneous Squamous Cell Carcinoma (cSCC)

Malignant keratinocytes invade dermis; papule/plaque/nodule ± ulceration, often hyperkeratotic
60 % arise from actinic keratoses; $9\text{–}14\%$ lifetime risk; $2\text{–}5\%$ metastasis

Actinic Keratosis (AK)

Rough scaly papule on sun-exposed skin; precursor to cSCC; actinic cheilitis = lip variant

Bowen’s Disease = cSCC in situ

Prevention

“Slip, Slop, Slap”: shirt, sunscreen, hat; avoid tanning beds

Nail Findings

Clubbing: angle base < $165^{\circ}$ , indicates pulmonary, cardiac, GI disease
Yellow nails ≠ always fungus (PAD, psoriasis, lymphedema)
Onychomycosis: thick, yellow, crumbly; confirm with KOH/culture
Terry nails, Beau lines, koilonychia ← systemic disease
Ingrown toenail ± paronychia; Onycholysis (nail plate separation)

Hair Findings

Alopecia areata: sudden well-demarcated patches; exclamation-point hairs; autoimmune
Traction alopecia: mechanical; frontal/temporal
Male pattern: bitemporal recession ± vertex; Female pattern: widened part with intact frontal line
Telogen vs. anagen hairs (trichogram)
Tinea capitis dermoscopy: comma, corkscrew, broken hairs

Special Populations & Must-Not-Miss Conditions

Neonates

Normal: erythema toxicum, slate gray (Mongolian) patches, salmon patches, milia
Concerning: café-au-lait (>6? think NF1), port wine stain, mottling, bruising, STIs, poor turgor

Children

Dermatitis (diaper, seborrheic, atopic), viral exanthems, impetigo, warts; evaluate petechiae in sick child, drug rashes, non-resolving lesions

Pregnancy

Normal: striae, melasma, linea nigra, palmar erythema, spider angiomas, skin tags
PUPPP/PEP (pruritic urticarial papules & plaques) – most common pruritic rash in pregnancy; starts in striae, spares umbilicus
Intrahepatic cholestasis of pregnancy: severe pruritus palms/soles, no primary rash, ↑ bile acids/LFTs; fetal risk (prematurity, stillbirth)
Table contrast of atopic eruption, polymorphic eruption, pemphigoid gestationis, cholestasis

Older Adults

Cherry angiomas, seborrheic keratoses, solar lentigines common benigns
Hidden bruises/burns → consider abuse
Skin cancer prevalence ↑; inspect thoroughly

Selected Common Diagnoses & Differentials

Pediculosis capitis: scalp pruritus; visualize lice; nit vs. hair cast
Tinea corporis: annular plaque with central clearing; DDx pityriasis rosea, nummular eczema, granuloma annulare, contact dermatitis
Herpes zoster: dermatomal vesicles → pustules → crusts; post-herpetic neuralgia; DDx HSV, cellulitis, urticaria, etc.
Acne rosacea: central facial erythema, papulopustules, flushing, telangiectasia ± ocular involvement; DDx acne vulgaris, lupus, seb derm
Psoriasis (plaque): well-demarcated silvery scale extensor surfaces; variants: inverse, palmoplantar, nail pitting/oil spots; DDx atopic, tinea, Lichen planus, secondary syphilis, etc.

Diagnostic Reasoning Pearls

Combine pattern recognition with OLDECARTS & VINDICATE S/P list
Always inspect “where the sun don’t shine” plus hair, nails, mucosa
Use objective tools: ruler, dermatoscope, Wood’s lamp, scrapings, biopsy
Detailed documentation = primary & secondary morphology, configuration, location, borders, color, size, texture
DDx template: 4 common, 3 do-not-miss, 2 zebras, 1 quick Google
When uncertain → biopsy or refer; ensure timely follow-up

Ethical / Practical Implications

Inclusive image resources reduce diagnostic error in skin of color
Systemic disease clues on skin can enable earlier internal disease detection
Sunscreen education critical across phototypes; counter “tanning bed” culture
Abuse recognition (infants, elders) requires vigilance during skin exam

Numerical / Statistical References

Actinic keratoses progress to cSCC in $\approx!10\%$ of lesions
Light-skinned individuals have $\sim80$ -fold higher cSCC risk than dark-skinned
Melanoma “Diameter” criterion: >6\,\text{mm} (“pencil eraser” rule)
Intrahepatic cholestasis stillbirth risk $1\text{–}2\%$ ; prematurity up to $60\%$

Formulas / Tests (Sample LaTeX)

Clubbing base angle: \text{Normal}\;\alpha \ge 180^{\circ};\;\text{Clubbing}\;\alpha < 165^{\circ}
Body Surface Area rule (burns) not covered but related: $A_{M} = 9\%$ each arm, etc.

Conclusion

Mastery of morphology + methodical history/exam = cornerstone of dermatologic diagnosis.
Equity, prevention, and systemic context are integral to advanced assessment.