Medicines for skin conditions fall into several groups that do different jobs. Using the wrong type is common, because different conditions can look alike, and treating a rash with the wrong product can make it harder to diagnose later.
- Steroid creams reduce inflammation in eczema and dermatitis. See steroid cream side effects.
- Antifungal creams treat ringworm, athlete’s foot and thrush. See antifungal cream side effects.
- Acne treatments such as benzoyl peroxide. See benzoyl peroxide side effects.
- Antiseptics and antibacterials for minor wounds and infections.
- Emollients and moisturisers, which are treatment rather than cosmetic in conditions like eczema.
Common side effects of this pharmacy medicine or category
- Stinging, burning or redness on application
- Dryness and peeling, expected with many acne treatments
- Itching or a rash from the product itself
- Increased sun sensitivity with some treatments
- Bleaching of fabrics with benzoyl peroxide, which surprises people
Some irritation is expected with acne treatments and usually settles if you start with a lower strength, apply less often at first, and moisturise. Stopping at the first sign of dryness is a common reason these are judged not to work.
Interactions and duplicate-ingredient risks
The most important point here is diagnosis, not interaction. A steroid cream applied to a fungal infection reduces the redness without treating the cause, so the rash may briefly look better while the infection spreads and changes appearance. That makes it harder for anyone to identify later.
If a rash has not been diagnosed, and particularly if it is spreading, circular, scaly or in a skin fold, ask before reaching for a steroid.
Do not layer several active products on the same area without checking, and be aware that some skin medicines are absorbed enough to matter over large areas. See topical medicine side effects.
Children, pregnancy, older adults and chronic medicine cautions
- Children absorb proportionally more, and some treatments are unsuitable by age.
- Pregnancy. Several acne treatments in particular are not suitable in pregnancy. Always check.
- Face, eyelids and skin folds, where thinner skin means more absorption and more irritation.
- Broken or weeping skin, where many products are unsuitable.
Warning signs and overdose concerns
Get emergency help for a rash that blisters or peels widely, sores in the mouth or eyes with fever, or difficulty breathing and swelling of the face or throat. These suggest a severe reaction rather than a local one. See medicine causing a blistering rash.
Stop and seek advice for a rash that spreads or worsens, signs of infection such as increasing pain with warmth, swelling or pus, or skin becoming thin and fragile.
See a doctor for any rash that has not improved in the time the label allows, keeps returning, or that you have been treating without a diagnosis.
Questions to ask a pharmacist before using it
- Does my rash actually look like what this treats?
- Could this be a fungal infection rather than eczema?
- How long should I use it before seeing a doctor?
- Is some irritation expected, or should I stop?
- Should I use a moisturiser alongside?
Related OTC and medicine-safety guides
- Topical medicine side effects
- OTC medicine side effects
- Over-the-counter medicine interactions
- When to see a doctor about an OTC medicine
- Report an OTC medicine side effect
See also medicines causing a skin rash.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.