Integumentary System
Abnormal Microscopic Findings
| Finding | Description | Diseases |
|---|---|---|
| Hyperkeratosis | ↑ Stratum corneum | Psoriasis |
| Parakeratosis | Nucleus in stratum corneum | Psoriasis |
| Hypergranulosis | ↑ Stratum granulosum | Lichen planus |
| Acanthosis | ↑ Stratum spinosum | Acanthosis nigricans |
| Acantholysis | Cleft in stratum spinosum | Pemphigus vulgaris |
| Spongiosis | Fluid in epidermis | Eczema |
| Exocytosis | Leukocyte in epidermis | - |
Rashes Associated with Infection
| Rash | Pathogens | Location |
|---|---|---|
| Condyloma accumulata | HPV | Genital |
| Condyloma lata | Treponema pallidum | Genital |
| Ecthyma gangrenosum | Pseudomonas aeruginosa | Anywhere |
| Erythema infectiosum [Fifth disease] | Parvovirus B19 | Face → Trunk & Extremities |
| Erythema marginatum | Group A streptococcus (GAS) | Trunk |
| Erythema migrans | Borrelia burgdorferi | Anywhere |
| Erythema multiforme | Mycoplasma & HSV | Anywhere |
| Erythema nodosum | Tuberculosis Leprosy Histoplasmosis | Anywhere |
| Hand-foot-mouth disease | Coxsackie A virus | Extremities → Trunk |
| Herpes simplex | HSV1 & HSV2 | Mouth & Genital |
| Herpes zoster [Shingles] | VZV | Dermatome |
| Measles | Measles virus | Head → Toe |
| Molluscum contagiosum | Poxvirus | Anywhere |
| Pityriasis rosea | Roseolovirus | Trunk |
| Rocky Mountain spotted fever | Rickettsia rickettsii | Extremities → Trunk |
| Roseola infantum | Roseolovirus | Trunk → Face & Extremities |
| Rubella | Rubella virus | Head → Toe |
| Seborrheic dermatitis | Malassezia | Anywhere |
| Tinea [Dermatophytosis] | Dermatophytes | Anywhere |
| Tinea versicolor | Malassezia | Trunk |
| Varicella [Chickenpox] | VZV | Face & Trunk → Extremities |
| Verruca vulgaris | HPV | Face & Extremities |
Rashes Associated with Non-Infectious Diseases
| Rash | Associations | Location |
|---|---|---|
| Acanthosis nigricans | Insulin resistance Visceral malignancy | Axilla & Neck |
| Atopic dermatitis | - | Joints |
| Erythema multiforme | Stevens-Johnson syndrome (SJS) Toxic epidermal necrolysis (TEN) | Anywhere |
| Erythema nodosum | Drugs Inflammatory bowel disease (IBD) Sarcoidosis Non-Hodgkins lymphoma | Anywhere |
| Erythema toxicum | Neonates | Face & Trunk & Extremities |
| Migratory thrombophlebitis Trousseau syndrome | Pancreatic adenocarcinoma | Veins |
| Necrolytic migratory erythema | Glucagonoma | Face & Extremities |
| Pyoderma gangrenosum | Inflammatory bowel disease (IBD) | Anywhere |
| Seborrheic dermatitis | Parkinson disease HIV infection | Anywhere |
| Seborrheic keratosis Leser-Trélat sign | Visceral malignancy | Trunk |
Benign Skin Rashes in Newborns
- Cradle cap
- Diaper rash
- Erythema toxicum
- Milia
- Mongolian spots
- Nevus simplex
- Strawberry angioma
Degrees of Skin Burns
| Degree | Thickness | Depth | Blanchable | Painful | Blistered | Color |
|---|---|---|---|---|---|---|
| 1 | Superficial | Epidermis | + | + | - | Erythema |
| 2 | Superficial partial | Papillary dermis | + | + | + | Erythema |
| Deep partial | Reticular dermis | ± | ± | ± | Erythema White | |
| 3 | Full | Subcutis | - | - | - | White Eschar |
Types of Skin Grafts
Types of Flaps
Blood Supply
- Random
- Axial
- Pedicled
- Free
Proximity
- Local
- Advancement
- Rotation
- Transposition
- Regional
- Distant
Composition
- Cutaneous
- Fasciocutaneous
- Musculocutaneous
- Osteocutaneous
Stages of Ulcers
| Stage | Thickness | Depth |
|---|---|---|
| 1 | Superficial | Epidermis |
| 2 | Partial | Dermis |
| 3 | Full | Subcutis |
| 4 | Full | Muscle & Bones |
Wagner Classification for Ulcers
| Stage | Description |
|---|---|
| 1 | Skin |
| 2 | Deep w/o abscess |
| 3 | Osteomyelitits |
| 4 | Localized gangrene |
| 5 | Extensive gangrene |
Wallace Rule of Nines
Etiology of Erythema Nodosum {DOSUM}
- Drugs
- Sulfa drugs
- NSAIDs
- Iodides
- Oral contraceptive pills (OCPs)
- Inflammatory bowel disease (IBD)
- Sarcoidosis
- Non-Hodgkins lymphoma
- Microbiology
- Tuberculosis
- Leprosy
- Histoplasmosis
Presentation of Lichen Planus {6P}
- Planar
- Purple
- Polygonal
- Pruritus
- Papules
- Plaques
Treatment of Atopic Dermatitis
- Moisturizers
- Topical corticosteroids
- Topical tacrolimus
- Phototherapy
Treatment of Urticaria
- Oral H1 antagonists
- Oral corticosteroids
Treatment of Contact Dermatitis
- Allergen avoidance
- Moisturizers
- Topical corticosteroids
- Topical tacrolimus
- Oral corticosteroids
Empirical Antibiotics for Cellulitis
- Anti-streptococcal penicillin
Empirical Antibiotics for Skin Abscess
- Anti-MRSA
Empirical Antibiotics for Necrotizing Fasciitis
- Anti-MRSA
- β-lactams & β-lactamase inhibitors
Carbapenems
Treatment of Acne Vulgaris
- Topical benzoyl peroxide
- Topical tretinoin
- Topical antibiotics
- Oral antibiotics
- Oral isotretinoin
Treatment of Seborrheic Dermatitis
- Topical tar
- Topical zinc pyrithione
- Topical selenium disulfide
- Topical antifungals
- Topical corticosteroids
- Oral antifungals
- Oral corticosteroids
Treatment of Verruca Vulgaris [Wart]
- Topical salicylic acid
- Topical trichloroacetic acid
- Topical podophyllin
- Topical 5-fluorouracil
- Topical imiquimod
- Cryotherapy
- Surgical excision
Treatment of Precancerous Skin Lesions
- Topical tretinoin
- Topical 5-fluorouracil
- Topical imiquimod
- Photodynamic therapy
- Cryotherapy
Types of Melanocytic Nevi
Features of Melanoma {ABCDE}
- Asymmetry
- Border irregularity
- Color variation
- Diameter > 6 mm
- Evolution
Types of Melanoma
- Superficial spreading melanoma
- Nodular melanoma
- Lentigo maligna melanoma
- Acral lentiginous melanoma
Management of Skin Cancer
| Cancer | Management |
|---|---|
| Squamous cell carcinoma | Cryotherapy Electrodesiccation Surgical excision Mohs micrographic surgery |
| Basal cell carcinoma | Cryotherapy Electrodesiccation Surgical excision Mohs micrographic surgery |
| Melanoma | Surgical excision |