Introduction

A compound obtained from the bark of the white willow and wintergreen leaves, and also prepared synthetically. It has bacteriostatic, fungicidal, and keratolytic actions. Its salts, the salicylates, are used as analgesics.

Uses

Salicylic acid is an acid used to treat acne, psoriasis, calluses, corns, keratosis pilaris, and warts.

Key additive in many skin-care products for the treatment of acne, psoriasis, callouses, corns, keratosis pilaris and warts.

Associated Conditions

Acne
Actinic Keratosis (AK)
Alopecia Areata (AA)
Atopic Dermatitis (AD)
Blackheads
Chronic Eczema
Chronic cutaneous lupus erythematosus
Corns
Dandruff
Dermatitis
Contact
Dermatitis
Eczematous
Dermatitis
Eczematous of the scalp
Discoid Lupus Erythematosus (DLE)
Foot Callus
Fungal skin infection
Furuncle
Hand Eczema
Hyperkeratosis
Hyperkeratosis follicularis et parafollicularis
Infections
Fungal
Infections
Fungal of the Skin Folds
Infections
Fungal of the face
Infections
Fungal of the feet
Infections
Fungal of the hand
Keratosis Palmaris et Plantaris
Lichen
Lichen Plano-Pilaris
Lichen Planus (LP)
Lichen simplex chronicus
Molluscum Contagiosum
Musculoskeletal Pain
Neurodermatitis
Palmo-Plantar Pustulosis
Plantar Warts
Pruritus
Psoriasis
Psoriasis Vulgaris (Plaque Psoriasis)
Psoriasis of the scalp
Rash
Ringworm of the Skin
Ringworm of the scalp
Seborrheic Dermatitis
Seborrhoeic Dermatitis of the Scalp
Skin Infections
Bacterial
Verrucous Psoriasis
Warts
Calluses
Corticosteroid-responsive dermatoses
Keratinization disorders
Scaling
Scaling of skin
Scalp seborrhea
Superficial Fungal skin infection
Keratolysis

Pharmacodynamics

Salicylic acid treats acne by causing skin cells to slough off more readily, preventing pores from clogging up. This effect on skin cells also makes salicylic acid an active ingredient in several shampoos meant to treat dandruff. Use of straight salicylic solution may cause hyperpigmentation on unpretreated skin for those with darker skin types (Fitzpatrick phototypes IV, V, VI), as well as with the lack of use of a broad spectrum sunblock. Subsalicylate in combination with bismuth form the popular stomach relief aid known commonly as Pepto-Bismol. When combined the two key ingredients help control diarrhea, nausea, heartburn, and even gas. It is also very mildly anti-biotic.

Mechanism of Action

Salicylic acid directly irreversibly inhibits COX-1 and COX-2 to decrease conversion of arachidonic acid to precursors of prostaglandins and thromboxanes. Salicylate's use in rheumatic diseases is due to it's analgesic and anti-inflammatory activity. Salicylic acid is a key ingredient in many skin-care products for the treatment of acne, psoriasis, calluses, corns, keratosis pilaris, and warts. Salicylic acid allows cells of the epidermis to more readily slough off. Because of its effect on skin cells, salicylic acid is used in several shampoos used to treat dandruff. Salicylic acid is also used as an active ingredient in gels which remove verrucas (plantar warts). Salicylic acid competitively inhibits oxidation of uridine-5-diphosphoglucose (UDPG) with nicotinamide adenosine dinucleotide (NAD) and noncompetitively with UDPG. It also competitively inhibits the transferring of the glucuronyl group of uridine-5-phosphoglucuronic acid (UDPGA) to a phenolic acceptor. Inhibition of mucopoly saccharide synthesis is likely responsible for the slowing of wound healing with salicylates.

Volume of Distribution

The volume of distribution is about 170 mL/kg of body weight.

Protein Binding

Salicylic acid is about 90% plasma protein bound.

Route of Elimination

About 10% is excreted unchanged in the urine.

Toxicity

Oral rat LD50: 891 mg/kg. Inhalation rat LC50: > 900 mg/m3/1hr. Irritation: skin rabbit: 500 mg/24H mild. Eye rabbit: 100 mg severe. Investigated a mutagen and reproductive effector.