Stretch marks

What it is

Stretch marks (striae) are lines in the skin where the deeper layer has been stretched and torn. They appear in growth spurts, pregnancy, weight change, bodybuilding and with steroid use. New marks are pink, purple or dark; old marks become pale and silvery.

How it works

Stretch marks form when skin stretches faster than its collagen and elastic fibres can adapt, tearing the dermis. New marks (striae rubrae) are red or purple-dark; old ones (striae albae) are pale and flatter.

Why it matters on darker skin

On darker skin new stretch marks may look dark brown or purple, and old ones may become lighter than the surrounding skin, which can be very noticeable.

Causes and triggers

Puberty, pregnancy, rapid weight change, body-building, and steroid creams or tablets.

What helps — and why it works

Most marks fade naturally over months to years. Early marks may respond somewhat to prescription retinoids (not in pregnancy) and some in-clinic treatments by experienced practitioners. Moisturisers feel nice but have limited proof of prevention. Early treatment of new marks: prescription retinoids (not in pregnancy) may help early marks. Expected timeline: months. Moisturiser massage: improves comfort; evidence for prevention is limited.

What to avoid and why

Be cautious of products that promise to "erase" stretch marks. Avoid laser or microneedling clinics without experience in darker skin, as burns and pigment changes are possible.

Common mistakes

• Expensive creams claiming to erase marks.
• Steroid 'toning' creams, which cause stretch marks.

Body care basics in a hot climate

Heat and humidity mean the body sweats more, which feeds the bacteria and yeasts that cause odour, rashes and some types of body acne. A daily lukewarm shower with a gentle, soap-free or mild cleanser, thorough drying of skin folds and between toes, and fresh, breathable cotton clothing prevent many problems. Moisturise straight after bathing while skin is still damp so water is sealed in; this matters even in humid months because frequent washing strips natural oils, and it matters most during harmattan. Avoid sharing towels, razors and sponges, which spread fungal and bacterial infections. When shaving, use a sharp blade, shave with the grain and do not stretch the skin; for curly hair a guarded trimmer is often better. Be cautious with body-lightening, 'carrot' or 'toning' lotions: many contain undeclared steroids or mercury. If a rash spreads, keeps coming back, or appears with fever, see a doctor rather than trying more creams.

Choosing body products

For most people an unscented, gentle cleanser and a plain moisturiser are enough. Antiperspirants containing aluminium salts are the most effective way to reduce sweating and are best applied at night to dry skin. Fragranced body sprays and deodorants are a common cause of allergy; fragrance-free options are kinder to sensitive skin. Aerosol products are easy to over-apply and some have been recalled for benzene contamination, so roll-ons and creams are a sensible default. For fungal rashes, plain antifungal creams such as clotrimazole are better than combination creams containing strong steroids, which can make infections spread. Always check for a NAFDAC number and a full ingredient list.

Questions to ask your doctor or pharmacist

Useful questions include: What do you think is causing this? Is it likely to come back, and how can I prevent it? Which products should I stop? How long before I should expect improvement, and when should I come back if it isn't better? Are there side effects to watch for? Is this treatment safe if I am pregnant, breastfeeding or for my child? Writing your questions down, bringing your products (or photos of their labels) and taking dated photos of the problem make an appointment much more useful.