What is a Salicylate?
A salicylate is a topical keratolytic agent that has been used for many years in the treatment of skin conditions like psoriasis and acne. 1 It works by reducing keratinocyte-to-keratinocyte binding and reducing the pH of the stratum corneum, which leads to reduced scaling and softening of plaques in psoriasis or helping to treat acne lesions.
Mechanism of Action
Salicylates function through several mechanisms:
- Reduce keratinocyte-to-keratinocyte binding
- Lower the pH of the stratum corneum
- Provide keratolytic effects that enhance penetration of other topical medications
- When used systemically (like aspirin), they have analgesic, antipyretic, and anti-inflammatory properties
Types and Formulations
Salicylates come in various forms:
- Topical preparations (0.5-2% concentration for acne)
- Higher concentrations (6% cream, lotion, gel, and 15% plaster) for other conditions
- Methyl salicylate (oil of wintergreen) in topical analgesic preparations
- Oral forms like acetylsalicylic acid (aspirin)
Clinical Uses
Dermatological Applications
- Acne vulgaris: Used alone or in combination with other drugs for symptomatic treatment 1
- Psoriasis: Helps reduce scaling and softening of psoriatic plaques 1
- Often combined with other topical therapies to enhance penetration due to its keratolytic effects
Dosing for Acne
- Apply 0.5-2% preparations 1-3 times daily
- Initially apply once daily, then gradually increase if necessary
- If dryness or peeling occurs, reduce to once daily or every other day 1
Safety Considerations
Contraindications
- Known sensitivity to salicylic acid or ingredients in the formulation
- Should not be used in combination with oral salicylate drugs due to risk of systemic toxicity 1
Adverse Effects
- Hypersensitivity reactions
- Salicylate toxicity
- Excessive erythema and scaling
- Contact dermatitis and anaphylactic reactions with methyl salicylate preparations
Special Populations
Pregnancy
- Pregnancy category C
- Appears to be a safe choice for localized psoriasis treatment during pregnancy 1
Nursing
- Discontinue nursing or the drug
- If used while nursing, avoid applying to chest area 1
Pediatric Use
- 6% cream, lotion, gel, and 15% plaster not recommended in children <2 years
- Increased risk of salicylate toxicity with prolonged use in children <12 years
- Use of salicylates in children with varicella infection or influenza-like illness is associated with increased risk of Reye syndrome 1
- Should generally be avoided in children due to greater risk of systemic absorption 1
Toxicity Concerns
Salicylate toxicity can occur with:
- Systemic absorption when applied to >20% of body surface area
- Patients with abnormal hepatic or renal function
- Prolonged use, especially in pediatric populations
- Concurrent use of multiple salicylate-containing products 1
In severe cases of salicylate poisoning, extracorporeal treatment (hemodialysis) may be necessary, particularly with high salicylate concentrations or signs of severe toxicity such as altered mental status 1.
Drug Interactions
- Acidifying agents
- Anticoagulants (particularly warfarin)
- Antidiabetic agents
- Aspirin
- Corticosteroids
- Diuretics
- Methotrexate
- Pyrazinamide
- Sulfur
- Uricosuric agents 1