ABPS Dermatology (BCD) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

SJS/TEN detachment thresholds

Stevens-Johnson syndrome has less than 10% epidermal detachment; overlap has 10% to 30%; toxic epidermal necrolysis has more than 30%. Drug withdrawal and supportive care are mainstays.

Anaphylaxis epinephrine dose

Intramuscular epinephrine 0.01 mg/kg, maximum 0.5 mg, into the anterolateral thigh; repeat every 5 to 15 minutes if needed. Antihistamines and corticosteroids are adjuncts, not first-line.

Chronic urticaria first-line

Chronic urticaria lasts more than six weeks. Second-generation H1 antihistamines are first-line; dose escalation may be used before adding biologics such as omalizumab.

Psoriasis Koebner phenomenon

Koebner phenomenon is the appearance of psoriasis lesions at sites of trauma, scratching, or surgery. It supports the isomorphic response concept and can worsen after skin injury.

DRESS syndrome features

Drug reaction with eosinophilia and systemic symptoms presents with rash, facial edema, fever, lymphadenopathy, eosinophilia, and organ involvement, often liver. HHV-6 reactivation can occur; stop the culprit drug.

Cellulitis purulent versus nonpurulent

Nonpurulent cellulitis is usually caused by beta-hemolytic streptococci and Staphylococcus aureus; purulent cellulitis or abscess requires drainage. Systemic toxicity and rapid spread warrant urgent evaluation.

Allergic contact dermatitis mechanism

Allergic contact dermatitis is a type IV delayed hypersensitivity reaction. Sensitized T cells respond to contact allergens, producing pruritic eczematous lesions; patch testing identifies the allergen.

Pemphigus vulgaris DIF

Pemphigus vulgaris shows intercellular IgG deposition in the epidermis on direct immunofluorescence, often described as a chicken-wire pattern. Serum ELISA for anti-desmoglein 1 and 3 may correlate.

Bullous pemphigoid DIF

Bullous pemphigoid shows linear IgG and C3 deposition along the basement membrane zone on direct immunofluorescence. Histology often shows subepidermal blister with eosinophils.

Lichen planus histology

Lichen planus histology shows hyperkeratosis, wedge-shaped hypergranulosis, saw-tooth rete ridges, a band-like lymphocytic infiltrate, and Civatte bodies at the dermoepidermal junction.

Psoriasis histology

Psoriasis shows parakeratosis, absent granular layer, regular acanthosis, thinned suprapapillary plates, dilated vessels, and Munro microabscesses or Kogoj spongiform pustules.

Breslow thickness definition

Breslow thickness is measured in millimeters from the granular layer of the epidermis, or from the base of the ulcer, to the deepest invasive melanoma cell.

Basal cell carcinoma histology

Basal cell carcinoma typically shows basaloid nests with peripheral palisading, stromal retraction clefts, and mucin. Nodular and superficial subtypes are common; biopsy confirms diagnosis.

Mohs micrographic surgery

Mohs surgery excises skin cancer in stages, maps the specimen, and examines 100% of peripheral and deep margins. It conserves tissue and is used for high-risk or cosmetically sensitive tumors.

Melanoma excision margins

Melanoma margins: in situ 0.5 to 1 cm; invasive up to 1 mm, 1 cm; 1 to 2 mm, 1 to 2 cm; deeper than 2 mm, 2 cm.

Lidocaine maximum dose

Lidocaine maximum dose is about 4.5 mg/kg without epinephrine and 7 mg/kg with epinephrine; epinephrine prolongs effect and reduces bleeding.

Fusiform excision ratio

A fusiform or ellipse excision generally uses a length-to-width ratio of about 3:1 and a 30-degree angle at each tip to close without dog-ears.

Suture removal timing

Typical suture removal is face 5 to 7 days, scalp 7 to 10 days, and trunk or extremities 10 to 14 days; lower extremity wounds may need longer.

Full-thickness graft requirement

A full-thickness skin graft requires a well-vascularized recipient bed and is used for defects on the face or areas needing better contour and less contraction than a split-thickness graft.

Infantile hemangioma treatment

Problematic infantile hemangiomas are treated with oral propranolol; superficial and small lesions may use topical timolol. Most involute spontaneously, but airway or vision involvement needs urgent care.

Port-wine stain laser

Port-wine stains are capillary malformations present at birth; pulsed dye laser is first-line. Segmental facial stains in the V1 distribution require evaluation for Sturge-Weber syndrome.

Tinea capitis treatment

Tinea capitis requires oral antifungal therapy such as griseofulvin or terbinafine; topical therapy alone is inadequate. Scaling, alopecia, and occipital lymphadenopathy are common.

Kawasaki disease criteria

Kawasaki disease requires fever for at least five days plus four of five features: conjunctivitis, oral changes, extremity changes, rash, and cervical lymphadenopathy; IVIG and aspirin reduce coronary risk.

Diaper dermatitis Candida signs

Candida diaper dermatitis shows beefy-red erythema with satellite pustules or papules in the diaper area, often after antibiotic use; topical nystatin or azole is used.

Hand-foot-mouth disease cause

Hand-foot-mouth disease is caused by enteroviruses, commonly coxsackievirus A16 or enterovirus 71. It produces oral vesicles and acral papulovesicles; treatment is supportive.

Botulinum toxin mechanism

Botulinum toxin cleaves SNARE proteins and blocks presynaptic acetylcholine release at the neuromuscular junction. Effect begins in 2 to 7 days and lasts about 3 to 6 months.

HA filler reversal

Hyaluronic acid fillers can be dissolved with hyaluronidase. This is essential for vascular occlusion, impending necrosis, or vision changes after filler injection.

Vascular occlusion filler emergency

Filler vascular occlusion presents with blanching, pain, dusky skin, or vision loss. Stop injection, do not massage blindly, and use hyaluronidase urgently for hyaluronic acid filler.

Chemical peel depth agents

Superficial peels use alpha-hydroxy acids or low-strength trichloroacetic acid; medium peels use higher trichloroacetic acid; deep peels use phenol. Higher Fitzpatrick types have greater pigment risk.

Laser hair removal target

Laser hair removal targets melanin in the hair follicle. Dark terminal hairs on light skin respond best; longer-wavelength lasers such as Nd:YAG are safer in darker skin.

Photodynamic therapy indication

Photodynamic therapy combines a photosensitizer such as aminolevulinic acid with light to treat actinic keratoses and some superficial nonmelanoma skin cancers; photosensitivity follows treatment.

Dynamic versus static rhytides

Dynamic rhytides appear with muscle contraction and respond to botulinum toxin; static rhytides persist at rest and often require fillers, resurfacing, or other collagen stimulation.