Iraqi Board Dermatology key terms

Intercellular edema of the epidermis that widens the spaces between keratinocytes and stretches desmosomes, producing visible intraepidermal vesicles in acute eczema.

Loss of cohesion between keratinocytes caused by breakdown of desmosomal attachments, creating rounded intraepidermal clefts or blisters as seen in pemphigus and Hailey-Hailey disease.

Pattern of inflammation in which lymphocytes obscuring the dermoepidermal junction damage basal keratinocytes, producing vacuolar change or lichenoid infiltrates with pigment incontinence.

Band-like lymphocytic infiltrate hugging the dermoepidermal junction with basal cell damage and apoptotic keratinocytes, classically seen in lichen planus and lichenoid drug eruptions.

Fine, white, lacy network on the surface of mucosal or cutaneous lichen planus lesions, best seen with magnification and reflecting hypergranulosis and altered keratinization.

Non-invasive magnified examination of skin lesions with polarized or fluid-immersion illumination that reveals subsurface structures and pigment patterns invisible to the naked eye.

Irregular, broadened pigment network with variable hole size and abrupt cut-offs on dermoscopy, a major clue to melanoma arising in a pigmented lesion.

Confluent blue-gray pigmentation overlying a whitish ground-glass area on dermoscopy, corresponding to compact orthokeratosis over dense dermal melanin or melanophages.

Separation of the epidermis on gentle lateral pressure at the edge of a blister or eroded skin, indicating intraepidermal acantholysis or a fragile dermoepidermal junction.

Test in which a fluorochrome-labeled antibody is applied to the patient's own frozen skin biopsy to detect in-vivo deposition of immunoglobulin or complement along the basement membrane or between keratinocytes.

Technique of incubating normal skin in concentrated saline to cleave the basement membrane at the lamina lucida, then mapping immune deposits to roof or floor to distinguish bullous pemphigoid from epidermolysis bullosa acquisita.

Absence of sweating in a patch of skin affected by leprosy owing to destruction of autonomic nerve fibers, a clue to tuberculoid or borderline tuberculoid disease.

Modified acid-fast staining method using peanut oil and a weaker acid decolorizer that preserves the waxy mycolic acids of Mycobacterium leprae in tissue sections.

Development of new lesions of a skin disease along lines of trauma or scratching, classically seen in psoriasis, lichen planus, and vitiligo.

Pinpoint bleeding produced when scale is removed from a psoriatic plaque, caused by elongation and tortuosity of dermal papillary capillaries close to the thinned suprapapillary plate.

Small collection of neutrophils within the parakeratotic stratum corneum of a psoriatic lesion, a characteristic histologic finding of active psoriasis.

Psoriasis Area and Severity Index, a weighted composite score combining body surface area involvement with erythema, induration, and scale in four body regions, used to grade severity and monitor treatment response.

Treatment using engineered antibodies or fusion proteins that block specific cytokines, receptors, or immune cells, such as TNF inhibitors, IL-17 inhibitors, and IL-23 inhibitors for psoriasis.

Mandatory latent tuberculosis assessment with interferon-gamma release assay or tuberculin skin test, plus chest imaging, before starting TNF inhibitors or other immunosuppressive biologics.

Appearance or worsening of a disease that the drug normally treats, such as new psoriasis or psoriasiform eruption during TNF inhibitor therapy.

Cutaneous adverse reaction to a medication, ranging from morbilliform exanthems and urticaria to severe reactions such as Stevens-Johnson syndrome or DRESS.

Drug reaction with eosinophilia and systemic symptoms, a severe delayed hypersensitivity with rash, fever, facial edema, lymphadenopathy, eosinophilia, and internal organ involvement, often to anticonvulsants or allopurinol.

Umbrella term for life-threatening drug-induced skin reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, and acute generalized exanthematous pustulosis.

Human leukocyte antigen allele strongly associated with abacavir hypersensitivity; screening before therapy nearly eliminates the reaction and illustrates pharmacogenetic risk stratification.

Erythema dyschromicum perstans, an acquired disorder of gray-blue hyperpigmented macules on the trunk and limbs, with a lichenoid interface histology and uncertain relationship to lichen planus.

Acquired symmetric hyperpigmentation of sun-exposed face, common in women and influenced by ultraviolet light, hormones, and genetic background.

Ultraviolet A-emitting examination lamp used to distinguish epidermal from dermal pigmentation and to detect fluorescence from organisms such as Microsporum or Corynebacterium minutissimum.

Dermoscopy of hair and scalp used to measure hair shaft caliber, identify perifollicular signs, and distinguish scarring from non-scarring alopecia.

Autoimmune non-scarring hair loss producing well-demarcated smooth patches, with exclamation-mark hairs and yellow dots on trichoscopy.

Dermoscopic examination of the nail unit, useful for evaluating longitudinal melanonychia and distinguishing benign pigmentation from subungual melanoma.

Group of inherited neurocutaneous syndromes with developmental abnormalities of skin and nervous system, including neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome.

Hypopigmented, polygonal macule with a leaf-like outline seen in tuberous sclerosis, often the earliest cutaneous sign and best detected with a Wood lamp.

Severe autosomal recessive ichthyosis with thick plate-like scales separated by deep fissures, ectropion, and respiratory compromise, caused by ABCA12 mutations.

Heterogeneous group of inherited mechanobullous disorders in which minor trauma causes blisters, classified by the level of cleavage as simplex, junctional, dystrophic, or Kindler syndrome.

Staging procedure in which the first draining node is identified with dye or radiotracer and examined histologically for metastasis, chiefly used in intermediate and high-risk melanoma.

Maximum depth of melanoma invasion measured in millimeters from the granular layer of the epidermis to the deepest tumor cell, the strongest predictor of prognosis.

Staged excision in which the surgeon maps, excises, and histologically examines 100 percent of the peripheral and deep margins of a tumor before reconstruction, sparing normal tissue.

Experimental study in which participants are allocated by chance to intervention or control groups, minimizing selection bias and allowing causal inference about treatment effect.

Reciprocal of the absolute risk reduction, expressing how many patients must receive an intervention for one additional patient to benefit.