Coeliac & Co.

“Gluten problem” gets used as a single label, but it actually covers a small family of different conditions. They can look alike from the outside — similar symptoms, similar diets — yet underneath they work in very different ways. Knowing which is which helps you get the right care, and helps the people around you understand what you’re dealing with.

Coeliac disease

Coeliac disease is an autoimmune condition, not an allergy or an intolerance. When gluten is eaten, the immune system mistakenly attacks the lining of the small intestine, flattening the tiny finger-like villi that absorb nutrients. Over time this can lead to deficiencies, anaemia, bone-density loss and a long list of other effects. It is diagnosed with blood tests (such as tTG-IgA) followed by a small-bowel biopsy, and managed with a strict, lifelong gluten-free diet. Even tiny amounts matter.

Non-coeliac gluten sensitivity (NCGS)

NCGS describes people who feel genuinely unwell after gluten — bloating, tiredness, headaches, brain fog — but who don’t have the antibodies or the intestinal damage that define coeliac disease, and don’t have a wheat allergy. The biology is still being understood, and there is no single confirmatory test; it is identified by ruling coeliac disease and wheat allergy out first, then seeing whether symptoms settle on a reduced-gluten diet. Many people manage it by eating gluten to their own tolerance rather than removing it absolutely.

Wheat allergy

A wheat allergy is a classic immune (IgE) allergic reaction to proteins in wheat. Reactions tend to come on quickly — within minutes — and can include itching, hives, swelling of the lips or throat, and in serious cases anaphylaxis. It is diagnosed with allergy testing (skin-prick or blood tests) and managed by avoiding wheat, though people with wheat allergy aren’t necessarily reacting to barley or rye the way a coeliac would.

Dermatitis herpetiformis (DH)

Dermatitis herpetiformis is the skin form of coeliac disease. It shows up as intensely itchy clusters of small blisters, often on the elbows, knees, buttocks and scalp. It’s driven by the same gluten-related immune process, and the great majority of people with DH also have the gut changes of coeliac disease, even if their digestion feels fine. The long-term treatment is a strict gluten-free diet; a medication called dapsone is sometimes used to calm the skin quickly while the diet does its slower work.

Refractory coeliac disease

This is a rare situation in which someone with confirmed coeliac disease continues to have symptoms and intestinal damage despite a genuinely strict gluten-free diet for a year or more, with other causes excluded. It’s uncommon, and the far more frequent explanation for ongoing symptoms is hidden gluten or cross-contact — which is reassuring. Genuine refractory disease needs specialist gastroenterology care, so it’s something to investigate with your medical team rather than self-diagnose.

Similar on the surface, different underneath

All of these can involve feeling unwell after gluten, and several are managed with a gluten-free diet. But the why differs — autoimmune damage, an allergic reaction, or a sensitivity we’re still learning about — and that “why” changes how serious it is, how strict you need to be, and what follow-up care looks like. That’s exactly why a proper diagnosis is worth pursuing rather than guessing.

A quick way to keep them straight

If it helps, think of it like this. Coeliac disease is the immune system attacking the body itself (autoimmune). A wheat allergy is the immune system over-reacting to wheat as if it were a threat (allergic). NCGS is real discomfort without either of those mechanisms that we can currently measure. Dermatitis herpetiformis is coeliac disease showing up on the skin. And refractory coeliac disease is the rare case where confirmed coeliac disease doesn’t settle on a strict diet. Different machinery, different management — same advice to get properly diagnosed.

What they have in common

Most of these conditions improve, fully or partly, when gluten or wheat is removed — which is exactly why people are tempted to skip testing and just “go gluten-free”. The trouble is that a gluten-free diet masks the very signals doctors rely on to tell these conditions apart. You can end up feeling better without ever knowing whether you have a lifelong autoimmune disease that needs annual blood tests and bone-density monitoring, or a sensitivity you could manage more flexibly. The diet is the same in the moment; the long-term care is very different.

This page is general information, not medical advice — work with your medical team.