Hives (urticaria)
Hives are raised, pale-centred welts with red edges that itch intensely. The defining feature is movement: an individual welt appears, lasts a few hours and fades, while new ones rise elsewhere. If you circle a welt with a pen, it will usually be gone within 24 hours. Triggers include foods, medicines, insect bites, heat, pressure and infection; often no cause is found. Most hives respond to a pregnancy-safe antihistamine prescribed by your doctor plus cool compresses.
Hives with swelling of the lips, tongue or eyelids, or any tightness in the throat or chest, is anaphylaxis until proven otherwise. Go to an emergency department immediately.
PUPPP (polymorphic eruption of pregnancy)
This is the most common pregnancy-specific rash. It appears in the third trimester, typically in a first pregnancy, and starts as itchy red bumps inside the stretch marks on the abdomen, sparing the skin immediately around the navel. It then spreads to the thighs, buttocks and arms. Unlike hives, individual lesions stay put for days and coalesce into plaques. It is harmless to the baby, and resolves within a few weeks of delivery. Emollients, cool oatmeal baths and prescribed topical steroids manage it.
Cholestasis of pregnancy
The critical one to catch. The hallmark is relentless itching, worst on the palms and soles and worst at night, with no primary rash at all — only scratch marks. It reflects impaired bile flow, carries real risks for the baby, and requires bile acid and liver function tests plus close monitoring. Any severe unexplained itching in the second half of pregnancy warrants a call to your obstetrician the same week.
Heat rash and fungal rashes
Heat rash (miliaria) is a fine pinprick rash in areas that sweat and rub — under the bust, the waistband, the neck folds — and settles with cooling, loose cotton and keeping the skin dry. Fungal intertrigo produces a well-defined red patch with a scaly edge and small satellite spots in the same folds, and needs an antifungal cream. Both are very common in the Indian summer and monsoon and are frequently mistaken for an allergy.
Pemphigoid gestationis
Rare but important. It starts as itchy welts around the navel, then develops tense, fluid-filled blisters. Unlike PUPPP it involves the navel and blisters. It needs specialist care and fetal monitoring.
What to do tonight
- Photograph the rash in daylight, and again the next day — movement versus persistence is the most useful clue you can give your doctor.
- Note where it started, whether the navel is involved, and whether palms and soles itch.
- Cool compresses, loose cotton, fragrance-free emollient. No hot showers.
- Call urgently for blisters, facial swelling, fever, breathing difficulty, or severe palm and sole itching.