Dermatology APEA 3P Exam Study Guide

Vocabulary flashcards covering primary lesions, inflammatory skin conditions, fungal infections, infestations, viral dermatoses, cysts, scars, and skin malignancies from the APEA 3P Dermatology study guide.

Macule

A flat primary skin lesion that is under $1\,cm$ in size.

Patch

A flat primary skin lesion that is over $1\,cm$ in size.

Papule

A raised primary skin lesion that is under $1\,cm$ in size.

Plaque

A raised primary skin lesion that is over $1\,cm$ in size.

Vesicle

A fluid-filled primary skin lesion that is under $1\,cm$ in size.

Bulla

A fluid-filled primary skin lesion that is over $1\,cm$ in size.

Pustule

A primary skin lesion containing pus.

Wheal

A transient edematous primary skin lesion.

Nodule

A deep, solid primary skin lesion.

Psoriasis

A T-cell-driven immune disorder in which keratinocytes turn over in days rather than weeks, presenting with sharply bordered red plaques with silvery scale on the elbows, knees, and scalp.

Auspitz sign

Pinpoint bleeding that occurs when a psoriasis scale is lifted.

Koebner phenomenon

The development of new skin lesions at sites of injury.

Atopic Dermatitis

A dermatologic condition involving a skin barrier defect plus IgE-mediated allergy, characterized by intense itch, lichenification, and flexural Involvement in older children and adults.

Atopic Triad

The clinical group consisting of atopic dermatitis, asthma, and allergic rhinitis.

Lichenification

Thickening of the skin with accentuated skin lines resulting from chronic itching and rubbing, commonly seen on flexures in atopic dermatitis.

Urticaria

A Type I allergic reaction where mast cells release histamine, producing dermal edema and raised, itchy, blanching wheals that move and individually last under $24\,hours$.

Open Comedones

Blackheads resulting from follicular plugging in acne.

Closed Comedones

Whiteheads resulting from follicular plugging in acne.

Isotretinoin

An oral systemic retinoid for severe acne that is a severe teratogen requiring participation in the iPLEDGE program, two contraceptive methods, and regular lipid and LFT monitoring.

Tinea Corporis

A superficial dermatophyte fungal infection of the skin presenting as a ring-shaped plaque with a raised scaly edge and a clear center.

Tinea Capitis

A dermatophyte fungal infection invading the hair shaft in school-age children, presenting as scaly patches of hair loss with black dots, kerion, and occipital nodes.

Kerion

A boggy, tender mass on the scalp associated with severe tinea capitis.

Scabies

An infestation caused by the Sarcoptes mite burrowing in the outer skin, causing severe night-time itch via a delayed hypersensitivity reaction and burrows in finger webs, wrists, waistline, and genitals.

Permethrin 5% cream

The standard topical therapy for scabies applied from the neck down for $8\text{ to }14\,hours$ and repeated in $1\text{ to }2\,weeks$.

Herpes Zoster

Reactivation of latent varicella-zoster virus in a dorsal root ganglion, causing burning pain followed by grouped vesicles on a red base in a single dermatome without crossing the midline.

Post-herpetic Neuralgia

Persistent neuropathic pain following herpes zoster managed with gabapentin, pregabalin, TCAs, or lidocaine patches.

Dermal (Epidermoid) Cyst

A keratin-filled sac lined with squamous epithelium that presents as a firm, mobile, dome-shaped nodule with a central punctum and cheesy, foul contents.

Keloid

A firm, shiny, rubbery scar formed by fibroblast overproduction of collagen that extends beyond the original wound edges.

Hypertrophic Scar

An exaggerated scar due to excess collagen that remains within the boundaries of the original wound.

Melanoma

A malignant skin lesion derived from melanocytes, where depth of invasion predicts outcome and risk factors include UV exposure, fair skin, atypical moles, and family history.

ABCDE Assessment Criteria

A diagnostic checklist for melanoma representing Asymmetry, Border irregular, Color varied, Diameter over $6\,mm$, and Evolving.