Skin Signs
This sign is positive when applying gentle lateral friction to normal-appearing skin causes the outer layer of the epidermis to easily slide or shear off.
What is the Nikolsky sign?
This double-stranded DNA poxvirus is the causative agent behind smooth, flesh-colored, dome-shaped papules featuring a distinct central umbilication
What is Molluscum contagiosum virus?
This primary lesion is defined strictly as a flat, even-level, non-palpable skin discoloration measuring less than 1.0 cm in diameter
What is a macule?
This oral, systemic retinoid is the most effective drug available for severe, scarring nodulocystic acne, but requires mandatory enrollment in the iPLEDGE program due to its extreme teratogenicity
What is Isotretinoin (Accutane)?
The definitive clinical diagnosis of acne vulgaris relies on identifying this fundamental primary lesion, which can be open (blackhead) or closed (whitehead)
What is a comedone?
This phenomenon describes the development of disease-specific lesions, like psoriasis, directly along the line of mechanical skin trauma or scratching.
What is the Koebner phenomenon?
his Gram-positive, catalase-positive, and coagulase-positive coccus is the most common global cause of honey-colored, crusted impetigo
What is Staphylococcus aureus?
These secondary lesions consist of thick, yellowish-white flakes representing an abnormal accumulation or shedding of dead stratum corneum cells
What is a scale?
For tinea capitis, topical antifungals fail to penetrate the hair shaft matrix, making this oral agent the mandatory first-line choice for children
What is oral Griseofulvin?
This condition presents as chronic, symmetric, hyperpigmented macules and patches on sun-exposed areas of the face and is strongly associated with pregnancy and oral contraceptive use
What is melasma?
Peeling a thick, silvery scale from a psoriatic plaque reveals droplets of pinpoint hemorrhage, a finding known by this eponymous name.
What is the Auspitz sign?
A microscopic KOH prep showing a "spaghetti and meatballs" pattern of hyphae and yeast cells identifies this lipophilic organism responsible for tinea versicolor
What is Malassezia furfur?
This leathery, thickened secondary skin lesion features highly accentuated skin lines and is caused directly by chronic scratching or rubbing
What is lichenification?
This class of topical medications is the first-line treatment for plaque psoriasis, but continuous long-term use can lead to adverse effects like skin atrophy, striae and psychosis
What are Topical Corticosteroids (or Topical Steroids)?
Recurrent, painful nodules in the axillae and groin that progress to draining sinus tracts, puckered scars, and double-headed comedones confirm a diagnosis of this severe disease
What is hidradenitis suppurativa?
If you pinch a dermatofibroma on either side, it will exhibit this classic, eponymous physical exam sign.
What is a dimple sign?
This virus is responsible for verruca vulgaris.
What is Human Papillomavirus (or HPV)?
This secondary lesion is defined as a deep, structural skin defect that completely penetrates the epidermis and enters the dermis, healing with a scar
What is an ulcer?
This first-generation cephalosporin is a standard oral first-line agent used to empirically treat uncomplicated, non-purulent cellulitis or erysipelas due to its strong coverage of MSSA and Streptococcus
What is Cephalexin (Keflex)?
This classic autoimmune disease presents with generalized, highly intense pruritus and large, tense subepidermal bullae that do not rupture easily, mostly affecting elderly patients
What is bullous pemphigoid?
This clinical screening concept states that a patient's nevi should look morphologically similar; any single mole that stands out from the rest warrants a biopsy.
What is the Ugly Duckling sign?
This dermatophyte is the most common fungal pathogen responsible for tinea corporis, classically presenting as an annular plaque with an active, scaling border and central clearing
What is Trichophyton rubrum?
This primary lesion is defined as a small, superficial, circumscribed elevation of the skin that is filled with purulent fluid or pus
What is a pustule?
First-line treatment for this nocturnal, intensely itchy infestation requires applying Permethrin 5% cream from the neck down, leaving it on overnight
What is Scabies?
To diagnose this condition, a clinician looks for an abscess, nodule, or chronic draining sinus tract located strictly in the sacrococcygeal cleft just above the buttocks
What is pilonidal disease (or a pilonidal cyst)?