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Dermnet NZ has a great glossary of dermatology terms. These all have images associated with them.
Physical Exam Findings
- Scale (hyperkeratosis): increase of dead cells on the skin surface with a dry appearance. Flakes of horny epithelium
- Crust: dried serum, blood or pus on the skin surface
- Papule: solid, palpable lesion which is < 10 mm in diameter
- Nodule: solid, palpable lesion which is > 10 mm in diameter
- Macule: flat, nonpalpable lesion which is < 10 mm in diameter, area of skin with color change < 10 mm
- Patch: flat, nonpalpable lesion which is > 10 mm in diameter, area of skin color change > 10 mm
- Plaque: well circumscribed palpable lesion which is usually raised and > 10 mm in diameter. Plaque comes from the french word for plate.
- Vesicle: blister filled with serous fluid or blood which is < 10 mm in diameter
- Bulla: blister filled with serous fluid or blood which is > 10 mm in diameter
- Wheal: elevated pale lesion caused by local edema and an indicator of urticaria
- Petechiae: pin point hemorrhagic spots which do not blanch
- Telangiectasia: dilated small superficial blood vessels
- Lichenification: thickened skin with distinct borders caused by chronic rubbing
- Macerated: swollen, soft, white skin secondary to an increase in water content. Think of sitting in the bathtub too long.
Signs, Labs and Tests
- Auspitz sign – punctate bleeding after a scale is removed
- Darier sign – an urticarial flare is produced by rubbing the skin
- Nikolsky sign – rubbing the skin can cause a blister
- Asboe-Hansen sign -pressing on a blister causes the dermis to continue to separate
- Patch test – show a hypersensitivity reaction for skin allergies
- Aceto whitening – applying acetic acid to warts will turn them white
- Biopsy – punch, shave, excisional or incisional for pathology
- Diascopy – a glass slide is pressed against the skin. Blanching indicates intact capillaries.
- Potassium hydroxide preparation (KOH prep) – Easy test to diagnose a fungal infection
- Wood’s lamp exam – examination of the skin under an ultraviolet light.
Dermatitis
- Inflammation of the skin
Atopic Dermatitis/Eczema
- Occurs predominantly in childhood and is outgrown during adolescence
- There is some relation to asthma and seasonal allergies
Clinical Presentation
- Dry itchy skin often involving the flexural surfaces (backs of knees, wrists, anterior elbow)
- Lichenified skin
Labs, Studies and Physical Exam Findings
- Distinct pattern of lichenified skin, typically involving the flexor surfaces (insides of elbows, behind the knees)
Treatment
- Prevention: Avoid dry air, limit bathing and use of soaps
- Topical cream
- Topical steroid
- Oral steroid
Contact dermatitis
- Think poison ivy
- Irritant vs allergic (hair dye vs poison ivy)
Clinical Presentation & Physical Exam findings
- Vesicles
- Crusted lesions
- Pruritus
- The location and distribution are keys to diagnosis
- Linear vesicles on the forearms or lower legs are often poison ivy
Labs, Studies and Physical Exam Findings
- Gram stain to rule out impetigo
Treatment
- Removal of causative agent
- Self limiting
- Calamine lotion
- Topical steroids
- Oral steroids
