Components

 epidermis
 dermis

• cutaneous appendages
  • sudoral glands
  • sebaceous glands
  • hair follicles and hair

 hypodermis (subcutis)

Pathology

 cutaneous developmental anomalies
 cutaneous lesions
 cutaneous syndromal lesions
 cutaneous diseases
 cutaneous tumors

Differential diagnosis of normal skin

 superficial fungal infection

• dermatophytosis
• tinea versicolor

 porokeratosis
 ichtyosis
 hypopigmentation

• vitiligo
• piebaldism
• chemical leukoderma
• nevus depigmentosus

 hyperpigmentation

• café-au-lait macule
• freckle
• melasma
• lentigo

 macular amyloidosis
 ochocerciasis
 dermal melanocytosis
 urticaria pigmentosa
 argyria
 urticaria
 anhidrotic ectodermal dysplasia
 anetoderma
 cutis laxa
 connective tissue nevus
 dermal mucinosis

• myxedema
• scleromyxedema

 atrophoderma
 lipoatrophy

References

 Tsuruta D, Green KJ, Getsios S, Jones JC. The barrier function of skin: how to keep a tight lid on water loss. Trends Cell Biol. 2002 Aug;12(8):355-7. PMID: #12191905#