Stratum corneum

Looks like

The outermost layer of the skin: 15 to 20 sheets of flat, dead cells, packed with keratin and bound by fats.

What it does

Forms the barrier that keeps water in and germs, chemicals and allergens out.

Keeping it well

Harsh soaps, hot water and frequent washing strip it, leaving skin dry, cracked and itchy; plain moisturisers repair it. Eczema is a weakened barrier.

Related conditions

• Acne vulgaris
• Alopecia (androgenetic & areata)
• Atopic dermatitis (eczema)
• Body dysmorphic disorder
• Boils and folliculitis
• Bullous pemphigoid
• Burns
• Candida & fungal infection
• Cellulitis
• Chickenpox (varicella)
• Chilblains (pernio)
• Cold sores (herpes simplex)
• Contact dermatitis
• Endemic fungal infections (histoplasmosis, coccidioidomycosis)
• Epidermoid (sebaceous) cyst
• Fungal skin infection (tinea)
• Hand, foot and mouth disease
• Heat exhaustion & heatstroke
• Hidradenitis suppurativa
• Hyperhidrosis
• Hypermobility and Ehlers–Danlos syndromes
• Hypothermia & frostbite
• Infantile haemangioma (strawberry mark)
• Kaposi sarcoma
• Keloid & hypertrophic scars
• Leishmaniasis
• Leprosy (Hansen's disease)
• Lichen planus
• Lichen sclerosus
• Lyme disease
• Mast cell activation & mastocytosis
• Measles
• Melanoma
• Melasma
• Mpox (monkeypox)
• MRSA and resistant staph infection
• Nappy (diaper) rash
• Necrotising fasciitis
• Onchocerciasis (river blindness)
• Parvovirus B19 (fifth disease)
• Pemphigus vulgaris
• Pilonidal sinus
• Pityriasis rosea
• Pressure ulcers & chronic wounds
• Psoriasis
• Psoriatic arthritis
• Radiation injury
• Rosacea
• Roseola (sixth disease)
• Rubella (German measles)
• Scabies & lice
• Scarlet fever
• Scrub typhus & rickettsial infections
• Seborrhoeic dermatitis & dandruff
• Seborrhoeic keratosis
• Shingles (herpes zoster)
• Skin cancer (basal cell & squamous cell)
• Stevens–Johnson syndrome / toxic epidermal necrolysis
• Sun damage & actinic keratosis
• Systemic lupus erythematosus
• Systemic sclerosis (scleroderma)
• Toxic shock syndrome
• Urticaria & angioedema
• Vitamin D deficiency
• Vitiligo
• Warts, molluscum and skin infections