Terms of skin disorders

Terms of skin disorders

Updated: 02/11/2022

© Jun Wang, MD, PhD

 

 

Clinical

Angioedema: Abrupt edematous changes of skin or mucosa, similar to urticaria

Changes of darkness of skin:

• Hyperpigmentation: Darker than normal surrounding skin
• Hypopigmentation: Lighter than normal surrounding skin

Crust: Hardened layer of a mixture of serum, blood, or purulent exudates, associated with erosion, or ulcer

Cyst: Encapsulated cavity or sac lined by true epithelium

Flat colored lesions:

• Macule: Circumscribed flat area of discoloration < 1 cm
  
• Patch: Flat area of discoloration > 1 cm

Lesions with discontinuous surface:

• Fissure: Crack through the epidermis and into the dermis, NO tissue loss
• Erosion: Discontinuity of skin causing partial loss of epidermis
• Excoriation: Deep linear scratch, commonly self-induced
  
• Ulceration: Discontinuity of skin causing complete loss of epidermis and possible loss of dermis

Lichenification: Thickening of skin due to chronic irritation (rubbing), may have discoloration

Onycholysis: Separation of nail plate

Poikiloderma: Skin atrophy with hypopigmentation and telangiectasia

Purulent: Containing or discharging pus

Raised lesions:

• Papule: Elevated flat topped area, < 10 mm
• Plaque: Elevated flat topped area, > 10 mm
• Nodule: Solid, palpable lesion > 10 mm
• Tumor: Solid palpable lesion > 2 cm 

Red discoloration:

• Erythema: Redness of skin due to increased blood flow, NO extravasation of blood cells, may blanch
• Purpura: Red discoloration of skin or mucosa, caused by extravasation of red blood cells

Scale: Dry, plate-like excrescence, associated with excess stratum corneum

Telangiectasia: Visible persistent dilation of small, superficial cutaneous blood vessels, may blanch

Vesicular lesions:

• Vesicle: Fluid filed area, < 10 mm
• Bullae: Fluid filled area > 10 mm
• Blister: Vesicle or bullae
• Pustule: Blister filled with pus

Wheals: Itchy, transient, elevated area with variable blanching and erythema, due to dermal edema

Special clinical terms

Ash-leaf spots: hypopigmented macules, which are usually elliptic in shape, seen in tuberous sclerosis

Shagreen patches: Orange-peel–textured area of connective tissue hamartoma most commonly over the lower trunk

Histology

Abnormal intercellular connections:

• Acantholysis: Loss of intercellular connections (desmosomes) between keratinocytes
• Spongiosis and vesicles: Widened intercellular or dermo-epidermal junctions

Abnormal keratosis:

• Dyskeratosis: Premature kerainization of keratinocytes below granular layer, often with eosinophilic cytoplasm
• Hyperkeratosis: Thickened cornified layer, often with prominent granular layer
• Hypergranulosis: Thickened granular layer, associated with intensive irritation (rubbing)
• Parakeratosis: Retaining nuclei of cells in cornified layer, nonspecific, associated with chronic irritation

Acanthosis: Thickening of epidermis

Atypia: Abnormal structural architecture or cellular morphology, including shape, size, and staining pattern, either reactive or neoplastic

Basaloid: With the appearance of basal layer epidermis, usually less cytoplasm, hyperchromatic nuclei

Cyst: Material-containing space lined by epithelium

Elastosis: Grayish discoloration of dermis, usually due to sun damage, commonly seen in sun-damaged skin, associated with actinic keratosis, and other skin cancers

Epithelioid: With the appearance of epithelial cells, usually round to oval nuclei

Hyperchromasia: Darker than normal nuclear stain, usually due to increased quantity of DNA, seen in dysplasia 

Intercellular bridge: Thread-like connection between widened intercellular spaces, containing desmosome, characteristic for squamous differentiation

Koilocyte: Changes of squamous cells characterized by enlarged nuclei with various degree of hyperchromasia, irregular nuclear membrane contour, and perinuclear halo (a clear area around nuclei), commonly associated with human papillomavirus infections

Pagetoid spread: Spread of tumor cells with relatively paler cytoplasm, either singly or in cluster, among benign epidermal keratinocytes with relatively darker cytoplasm, as seen in Paget disease.

Palisade: Monolayer of relatively long cells or organisms arranged loosely perpendicular to a surface and parallel to each other

Pleomorphism: Variations of morphology, usually a sign of high-grade tumor cells

Psoriasiform hyperplasia: Regular elongation of rete ridges and suprapapillary thinning, nonspecific, seen at psoriasis, or results of chronic irritation

Squamous pearl: Keratinized structure with concentric layers of atypical squamous cells, usually seen in squamous cell carcinoma

Back to contents