CLINICAL

HISTOLOGIC

Dryness (roughness)

Increased compaction of stratum corneum, increased thickness of granular cell layer, reduced epidermal thickness, reduced epidermal mucin content

Actinic keratoses

Nuclear atypia, loss of orderly, progressive keratinocyte maturation; irregular epidermal hyperplasia and/or hypoplasia; occasional dermal inflammation

Irregular pigmentation

Freckling

Reduced or increased number of hypertrophic, strongly DOPA-positive melanocytes

Lentigines

Elongation of epidermal rete ridges; increases in number and melanization of melanocytes

Guttate hypomelanosis

Reduced number of atypical melanocytes

Diffuse irreversible hyperpigmentation

Increased number of DOPA-positive melanocytes and increased melanin content per unit area and increased number of dermal melanophages

Wrinkling

Fine surface lines

None detected

Deep furrows

Contraction of septae in the subcutaneous fat

Stellate pseudoscars (see eFig. 108-4.3 in on-line edition)

Absence of epidermal pigmentation, altered fragmented dermal collagen

Elastosis (fine nodularity and/or coarseness)

Nodular aggregations of fibrous to amorphous material in the papillary dermis

Inelasticity

Elastotic dermis

Telangiectasia

Ectatic vessels often with atrophic walls

Venous lakes

Ectatic vessels often with atrophic walls

Purpura (easy bruising)

Extravasated erythrocytes and increased perivascular inflammation

Comedones

Ectasia of the pilosebaceous follicular orifice

Sebaceous hyperplasia

Concentric hyperplasia of sebaceous glands

^aBasal cell carcinoma and squamous cell carcinoma also occur in photoaged skin but, unlike the table entries, affect only a minority of individuals.