Salicylic Acid (Various generics (often extemporaneously compounded, alone or combined with a corticosteroid or coal tar))

1. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with topical therapy and alternative medicine modalities for psoriasis severity measures

• Keratolytic scale removal to flatten thick, scaly psoriatic plaques, and for hyperkeratosis of the palms and soles.
• Used on the scalp (shampoo, lotion, or solution) just before a corticosteroid or vitamin D analogue application to improve penetration, and on the trunk/extremities as an adjunct when significant scale limits response to a topical corticosteroid alone.
• Not indicated as a stand-alone treatment for the underlying inflammatory component of psoriasis -- it addresses scale, not the immune-mediated plaque itself.

• There is no theoretical mechanistic reason for concern with topical use during pregnancy, but human safety data are limited; use the smallest effective amount over the smallest area for the shortest duration needed, and avoid extensive use over large body-surface areas given uncertain systemic absorption at high doses.

• Systemic absorption of topical salicylic acid can vary depending on the concentration, vehicle, and surface area treated; because of this variability, it is generally not recommended for extensive use while breastfeeding. Avoid direct contact between a treated area and the infant's skin or mouth.

• No specific dosing differences are established; older, thinner, or more fragile skin may be more prone to irritation.

• Use with particular caution in children, and avoid extensive use over large body-surface areas -- prolonged use of higher concentrations over large areas has been associated with salicylate toxicity, and children are at greater risk given a higher skin-surface-to-body-mass ratio.

• Cream, lotion, or gel (3-10%): apply once or twice daily to affected, scaly areas.
• Shampoo (1.8-3%): apply to wet hair and scalp once or twice weekly, leave on briefly per product instructions, then rinse; applying shampoo to dry hair/scalp before adding water can improve removal of oil-based scalp preparations.
• When combined with a corticosteroid or vitamin D analogue, apply the salicylic acid preparation first to remove scale, allow it to work, then apply the second agent -- this improves the second agent's penetration but adds complexity that can reduce adherence, so weigh the marginal benefit against the practical burden for each patient.

If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.

• Prolonged use over large body-surface areas, especially in children, can cause salicylate toxicity (tinnitus, hyperventilation, metabolic disturbance) from cutaneous absorption -- limit the treated surface area and duration accordingly, and seek urgent medical assessment if toxicity is suspected.

• Local irritation, stinging, or erythema at the application site.
• Scaling or peeling beyond what is intended.
• Dryness.

Serious side effects require immediate discussion with the prescriber or emergency care.

• Salicylate toxicity with prolonged use over large areas, particularly in children -- see Overdose.
• Contact dermatitis or hypersensitivity reactions.

• Use with caution over large body-surface areas or for prolonged periods, particularly in children, given the risk of cutaneous salicylate absorption.
• Avoid application to broken, infected, or heavily inflamed skin, which can increase absorption and irritation.
• Avoid concurrent use of other keratolytic or exfoliating products on the same area, which can compound irritation.

• Hypersensitivity to salicylic acid or salicylates.
• Known aspirin/salicylate allergy is a relative contraindication given the shared chemical class.

• No clinically significant systemic drug-drug interactions are described at typical topical doses; theoretical additive salicylate exposure exists with concurrent high-dose oral salicylate (e.g., ASA) use, most relevant if applied over large body-surface areas.

• Not applicable -- this is a topical product, not taken by mouth.

• Once or twice daily (cream/lotion/gel) or once or twice weekly (shampoo); no relationship to meal timing.

• Store at controlled room temperature, out of reach of children.

• This product helps soften and remove the thick, flaky scale that builds up on psoriasis patches, making other treatments (like a steroid cream) work better underneath it.
• Apply as directed, usually once or twice a day, or use the shampoo version once or twice a week if it is for your scalp.
• Do not use it over large areas of your body for a long time, especially in children, since too much can be absorbed through the skin.
• Common effects include mild stinging, redness, or extra peeling where it is applied.
• Tell your pharmacist if you are allergic to aspirin or other salicylates before starting this product.