What are the signs and symptoms of gluten intolerance?

Signs of Gluten Intolerance

Gluten intolerance presents with a broad spectrum of gastrointestinal and extraintestinal manifestations, with many patients showing non-classic symptoms rather than the traditional diarrhea and malabsorption pattern, making clinical suspicion essential for diagnosis.

Gastrointestinal Manifestations

Classic Intestinal Symptoms

• Diarrhea is the most common classic symptom, frequently accompanied by abdominal pain 1, 2
• Bloating and flatulence are common complaints that may occur with or without diarrhea 1, 2
• Abdominal pain occurs frequently and often responds to gluten exclusion 2
• Alternating diarrhea and constipation is a common pattern that responds to a gluten-free diet 2
• Weight loss or poor weight gain, particularly important in children, is a significant concern 1

Important Clinical Context

While diarrhea is most frequent, steatorrhea occurs in only one-fifth of patients, highlighting that classic malabsorption symptoms are actually uncommon 2. Most patients present with atypical gastrointestinal complaints rather than the traditional presentation 3, 2.

Extraintestinal Manifestations

Hematological Signs

• Iron deficiency anemia that is resistant to oral iron supplementation affects 48% of adults at presentation and may occur without any gastrointestinal symptoms 1, 4, 3
• Anemia of various types including other nutritional deficiencies 5

Musculoskeletal Manifestations

• Osteopenia and osteoporosis occur frequently in untreated disease, with prevalence ranging from 1.7% to 42% depending on demographics 4
• Increased fracture risk shows 60-100% excess compared to the general population before diagnosis 4
• Bone or joint pain and diffuse musculoskeletal pain 6, 5

Neurological and Psychiatric Signs

• Fatigue and weakness are common complaints related to anemia or general malnutrition 1, 4
• Irritability and inability to concentrate, particularly noted in children 1
• Depression and psychiatric disorders affect approximately 24% of adults 4
• Peripheral neuropathy and cerebellar ataxia are well-established neurological complications 4, 5
• Epilepsy and seizures documented in both children and adults 4

Dermatological Manifestations

• Dermatitis herpetiformis (herpetiform dermatitis) is a specific cutaneous manifestation that may occur independently or with intestinal disease 5
• Cutaneous vasculitis may occur 5

Reproductive Issues

• Infertility and recurrent miscarriages are associated with untreated celiac disease 1, 4, 3
• Adverse pregnancy outcomes occur in undiagnosed disease 4

Growth and Development

• Growth failure and short stature in children is the most common extraintestinal manifestation (33% of pediatric cases) 1, 4
• Failure to thrive in children 3

Hepatic Manifestations

• Transaminitis (elevated liver enzymes) may be a presenting sign 3

Non-Celiac Gluten Sensitivity

Gluten intolerance without celiac disease affects up to 6% of the population, and overall nonceliac wheat sensitivity may affect 10% of individuals 7. This condition:

• Is not genetically linked and does not trigger an allergic response 7
• Presents with similar symptoms as celiac disease including bloating, abdominal pain, and diarrhea 7, 8
• Activates the innate immune system and multiple inflammatory pathways 7
• May involve wheat proteins called amylase trypsin inhibitors (ATIs) in addition to gluten 7

Critical Clinical Pitfalls

Diagnostic Delays

• Many patients present with non-specific or extraintestinal symptoms rather than classic gastrointestinal complaints, leading to delayed diagnosis 1, 4
• Only approximately 24% of those with celiac disease are diagnosed, creating a "celiac iceberg" of undiagnosed cases 1, 4
• Severe inflammation of the small bowel can be present without any gastrointestinal symptoms 6

Overlapping Conditions

• Symptoms may overlap with irritable bowel syndrome, lactose intolerance, or microscopic colitis 7
• Patients on a gluten-free diet before testing may have false negative results on serological tests 1

High-Risk Groups Requiring Screening

• First-degree relatives of people with celiac disease 1
• Patients with type 1 diabetes (5-10% prevalence of celiac disease) 1, 4
• Individuals with autoimmune thyroid disease (3% prevalence) 4, 5
• Patients with Down syndrome (5.5% confirmed prevalence) 1, 4
• Patients with Turner syndrome (6.3% prevalence) 4

Special Considerations in Type 1 Diabetes

Patients with type 1 diabetes and concurrent gluten intolerance may present with:

• Unpredictable blood glucose levels despite adherence to insulin regimen 1
• Unexplained hypoglycemia episodes 1
• Deterioration in glycemic control without obvious cause 1

Response to Gluten-Free Diet

When gluten intolerance is present, patients have substantial and rapid improvement of symptoms with a gluten-free diet 2:

• Diarrhea responds in most patients, usually within days, with mean time to resolution of 4 weeks 2
• Abdominal pain and bloating resolve with dietary adherence 2
• The benefit of gluten exclusion is equally apparent in men and women 2