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Alopecia
- Hair loss disorder with multiple etiologies
Clinical Presentation
Alopecia areata
- Sudden onset
- Patchy, well-circumscribed, non-scarring hair loss
- Smooth scalp skin
- Exclamation-point hairs (short broken hairs that taper proximally)
- Associated with autoimmune disease (thyroid disease, vitiligo)
- Nail pitting may be present
Androgenetic alopecia
- Gradual, progressive thinning
- Men: receding hairline, vertex thinning
- Women: diffuse crown thinning with preserved frontal hairline
- Strong family history
Telogen effluvium
- Diffuse hair shedding
- Occurs 2–3 months after physiologic stress
- Illness
- Surgery
- Pregnancy
- Emotional stress
- Positive hair-pull test
- Scalp appears normal
Tinea capitis
- Patchy hair loss with scale
- Broken hairs (“black dots”)
- Common in children
- Posterior cervical lymphadenopathy
Scarring alopecia
- Permanent hair loss
- Loss of follicular openings
- Inflammatory or autoimmune destruction
Diagnostics
- Clinical diagnosis
- KOH or fungal culture if scale present
- Consider TSH if autoimmune disease suspected
- Preserved follicles = non-scarring
- Absent follicles = scarring
Treatment
Alopecia areata
- Intralesional corticosteroids (first-line)
- Topical steroids as alternative
Androgenetic alopecia
- Minoxidil
- Finasteride (men)
- Spironolactone (women)
Telogen effluvium
- Reassurance
- Remove underlying stressor
Tinea capitis
- Oral antifungals (terbinafine or griseofulvin)
- Topicals alone ineffective
Exam Keys
- Patchy, smooth hair loss → alopecia areata
- Diffuse shedding after stress → telogen effluvium
- Gradual thinning over years → androgenetic alopecia
- Child + scale + broken hairs → tinea capitis
- Loss of follicular openings = scarring and permanent
Onychomycosis
- Fungal infection of the nail (dermatophytes most common)
- Toenails affected more often than fingernails
Risk Factors
- Older age
- Diabetes
- Peripheral vascular disease
- Immunosuppression
- Tinea pedis
- Nail trauma
- Occlusive footwear
Clinical Presentation
- Thickened, brittle nails
- Yellow-brown discoloration
- Subungual debris
- Onycholysis
- Often asymptomatic
- Thickened, yellow, crumbly toenails in the stem
Diagnostics
- KOH prep
- Fungal culture
- Nail clipping with PAS stain
Treatment
- First-line: oral terbinafine
- Alternatives: itraconazole, fluconazole
- Topical agents (ciclopirox, efinaconazole) for mild disease only
- Fingernails: ~6 weeks
- Toenails: ~12 weeks
- Monitor LFTs with systemic therapy
Exam Keys
- Thickened yellow toenails → onychomycosis
- Oral therapy required
- Terbinafine = first-line
- Topicals usually fail
Paronychia
- Infection of the lateral or proximal nail fold
- Acute or chronic
Risk Factors
- Nail biting
- Manicures or artificial nails
- Frequent wet work
- Diabetes
- Immunosuppression
Clinical Presentation
- Acute: rapid onset pain, erythema, swelling, possible purulence
- Chronic: swelling, erythema, nail dystrophy >6 weeks
- Usually Staphylococcus aureus (acute)
- Tender swelling along nail margin in the stem
Diagnostics
- Clinical diagnosis
Treatment
- Warm soaks
- Incision and drainage if abscess present
- Oral antibiotics covering Staph
- Chronic: avoid moisture, topical steroids ± antifungals
Exam Keys
- Nail fold infection → paronychia
- Acute = bacterial
- Chronic = inflammatory
- Abscess → drainage
Felon
- Deep infection of the fingertip pulp
- Closed-space infection with risk of ischemia
Risk Factors
- Puncture wounds
- Splinters
- Untreated paronychia
- Diabetes
- Immunosuppression
Clinical Presentation
- Severe throbbing pain
- Tense swelling of fingertip pad
- Pain out of proportion to exam
Diagnostics
- Clinical diagnosis
- X-ray if concern for foreign body or osteomyelitis
Treatment
- Urgent incision and drainage
- Oral antibiotics covering Staph and Strep
Exam Keys
- Pulp space infection → felon
- Severe throbbing pain = key clue
- Requires drainage
Pigment Disorders
Melasma
- Acquired hyperpigmentation of sun-exposed skin
Risk Factors
- Pregnancy
- Oral contraceptives
- Estrogen therapy
- Sun exposure
Clinical Presentation
- Symmetric brown or gray-brown facial patches
- Cheeks, forehead, upper lip
- No scale or inflammation
Diagnostics
- Clinical diagnosis
Treatment
- Sun protection
- Hydroquinone (first-line)
- Retinoids or azelaic acid
Exam Keys
- Symmetric facial hyperpigmentation → melasma
- Pregnancy/OCP association
- Sun worsens it
Vitiligo
- Loss of melanocytes causing depigmented skin
Risk Factors
- Autoimmune disease
- Family history
Clinical Presentation
- Well-demarcated white patches
- Face, hands, periorificial areas
- May have white hair (poliosis)
Diagnostics
- Clinical diagnosis
- Wood’s lamp accentuates lesions
Treatment
- Topical corticosteroids
- Topical calcineurin inhibitors for face/intertriginous areas
- Phototherapy for extensive disease
Exam Keys
- Depigmented patches → vitiligo
- Autoimmune associations common
Chronic Inflammatory Derm
Acanthosis Nigricans
- Velvety hyperpigmented plaques
- Marker of insulin resistance
Risk Factors
- Insulin resistance
- Obesity
- Type 2 diabetes
- PCOS
- Malignancy (rare)
- Higher prevalence in African American, Hispanic, Native American patients
Clinical Presentation
- Dark, velvety plaques
- Posterior neck, axillae
- Abrupt onset raises concern for malignancy
Diagnostics
- Clinical diagnosis
- Evaluate for insulin resistance
Treatment
- Weight loss
- Improve glycemic control
Exam Keys
- Velvety plaques on neck/axillae → acanthosis nigricans
- Think insulin resistance
- Sudden onset → malignancy workup
Stasis Dermatitis
- Chronic inflammatory dermatitis from venous insufficiency
Risk Factors
- Chronic venous insufficiency
- Varicose veins
- Prior DVT
- Obesity
- Prolonged standing
Clinical Presentation
- Erythema, scaling, pruritus
- Brown discoloration (hemosiderin)
- Medial ankles and lower legs
- Chronic edema
Diagnostics
- Clinical diagnosis
Treatment
- Compression stockings
- Leg elevation
- Topical corticosteroids
Exam Keys
- Lower leg dermatitis + edema → stasis dermatitis
- Compression = first-line
- Not infectious
