Published by Dr. Lasi's Skin & Hair Clinic
A dark neck or underarms is often treated as a cosmetic problem and scrubbed hard with lemon, baking soda or bleach. But darkening in body folds can be a sign of what is happening inside the body. Finding the cause is the first step to lasting improvement.
Common causes
Acanthosis nigricans
This is the most common cause. The skin of the neck, underarms, groin or knuckles becomes darker, thicker and velvety. It is often linked to insulin resistance, the state in which the body needs more insulin to control blood sugar. Insulin resistance is associated with weight gain, prediabetes, type 2 diabetes and polycystic ovary syndrome (PCOS). It can also run in families and, less commonly, be caused by some medicines or other medical conditions.
Friction and hair removal
Repeated shaving, waxing, tight clothing and rubbing can irritate the skin and leave it darker.
Reactions and inflammation
Deodorants, perfumes, fungal infections and eczema can inflame the skin, and the inflammation can leave dark marks.
Sun exposure
The back and sides of the neck are often exposed to strong sun, which adds tanning.
Why the health link matters
When acanthosis nigricans appears, especially with skin tags, weight gain, irregular periods or a family history of diabetes, it is worth checking blood sugar and related tests. Treating insulin resistance through diet, physical activity, weight management and medical treatment where needed often lightens the skin gradually on its own. Creams alone, without addressing the cause, tend to give limited and short-lived results.
What to avoid
- Scrubbing hard with loofahs, sugar, salt or baking soda
- Lemon juice, bleach and other harsh home remedies
- Unlabelled 'whitening' creams, which may contain steroids or mercury
- Repeated waxing or shaving over irritated skin
How dermatologists treat it
At Dr. Lasi's, neck and underarm pigmentation is treated after an examination and, when indicated, blood tests. Options may include:
- Treating the underlying cause, with referral to a physician or gynaecologist when needed
- Prescription creams that exfoliate and lighten the skin
- Chemical peels to remove thickened, pigmented surface skin
- Laser toning or carbon peel for pigment
- Fractional laser in selected cases with thickened skin
- Laser hair reduction for those whose darkening is worsened by shaving or waxing
How long does improvement take?
Improvement is gradual, usually over several months. If the cause continues, the darkening can return, so lifestyle changes and maintenance care are part of the plan.
Daily care
- Wash gently with a mild cleanser and pat dry
- Keep body folds dry in hot, humid weather
- Wear loose, breathable cotton clothing
- Use a fragrance-free moisturiser
- Use sunscreen on the neck when outdoors
Get the cause of a dark neck checked. Book an appointment or call +91 81398 82226.
This article is for general information. For advice about your own skin or hair, please book a consultation.