Table 1.

Collagen distribution and function in skin

Collagen	% Total	Location	Function	Skin disorders
I	80	Dermis	Maintains skin structure and tissue integrity	Mutations resulting in osteogenesis imperfecta and Ehlers Danlos syndrome
III	15	Dermis	Maintains skin structure and integrity	Deficient mice display very severe spontaneous skin wounds and not uniformed the diameters of the collagen fibrils
			Provide tensility, flexibility and softness
			Determines the collagen fibril diameter
IV	2–4	Basement membrane vessels	Separates dermis-epidermis	Mutations resulting in Alport syndrome
			Supports cells
V	<1	Basement membrane dermis	Bridges and stabilizes the epidermal–dermal interface	Defective product in most cases of Ehlers Danlos syndrome
			Contributes to epidermis differentiation	Abnormal deposition in dermis correlates with skin thickening
VI	<1	Dermis papillary	Provides resistance to tensile stress	Defective linked to atopic dermatitis and trichothiodystrophy with dry, scaly ichthyotic skin
			May function in the maintaining the barrier function of the skin
VII	<1	Basement membrane	Stabilizes the association of the lower part of the basement membrane to the underlying dermis	Mutation resulting in recessive dystrophic epidermolysis bullosa and epidermolysis bullosa acquisita
XIV	<1	Dermis hair follicles	May act in modulating cell-matrix adhesion	Mature skin with mutation exhibits reduced mechanical properties
XVI	<1	Papillary dermis	Anchores microfibrils to basement membranes	Mutation resulting in epidermolysis bullosa
XVII (BP180)	<1	Basal keratinocytes	Maintains adherence of the epidermis to the basement membrane	Mutation resulting in epidermolysis bullosa, Pemphigoid immunobullous diseases