What is the best course of treatment for a 41-year-old female patient with new onset eczema and worsening abdominal pain and diarrhea?

Management of New Onset Eczema with Worsening Abdominal Pain and Diarrhea

Immediate Priority: Rule Out Immune Checkpoint Inhibitor Toxicity

If this patient is on any immune checkpoint inhibitor therapy (anti-PD-1, anti-PD-L1, or anti-CTLA-4), this presentation represents grade 2-3 immune-related adverse events requiring immediate corticosteroid therapy and potential hospitalization. 1

• Hold all immune checkpoint inhibitor therapy immediately if the patient has grade 2 colitis symptoms (abdominal pain with 4-6 bowel movements per day) 1
• Start prednisone 1 mg/kg/day (or equivalent methylprednisolone) immediately for diarrhea with abdominal pain 1
• Obtain stool studies (infectious workup including C. difficile), inflammatory markers (CRP, ESR, fecal calprotectin), and consider imaging/endoscopy 1
• For the eczema component: apply class I topical corticosteroid (clobetasol propionate or betamethasone dipropionate) to the body and class V/VI steroid (hydrocortisone 2.5%) to the face, plus oral antihistamines (cetirizine 10 mg daily or hydroxyzine 10-25 mg QID) 1
• If no improvement in 48 hours, escalate to prednisone 2 mg/kg/day and consider hospitalization 1

If NOT on Immune Checkpoint Inhibitors: Evaluate for Inflammatory Bowel Disease

New onset eczema with concurrent gastrointestinal symptoms in a 41-year-old raises concern for inflammatory bowel disease, as atopic eczema is causally associated with IBD, particularly Crohn's disease. 2

Diagnostic Workup

• Obtain complete blood count, serum albumin, ferritin, C-reactive protein, liver enzymes, and renal function 1
• Send stool studies for C. difficile toxin, bacterial culture, and ova/parasites 1
• Measure fecal calprotectin to assess for intestinal inflammation 1
• Consider colonoscopy with histologic confirmation as the diagnostic cornerstone, especially given the patient's age and new symptom onset 1
• Cross-sectional imaging (CT) is appropriate to rule out ischemic colitis, diverticular disease, or other acute pathology 1

Immediate Symptomatic Management

Aggressive fluid resuscitation is the first priority for diarrhea with abdominal pain. 3

• Assess hydration status by checking for orthostatic hypotension, decreased skin turgor, dry mucous membranes, decreased urination, and altered mental status 3
• Administer oral rehydration solution (ORS) for mild-to-moderate dehydration 1, 3
• Use intravenous isotonic crystalloids (lactated Ringer's or normal saline) in 20 mL/kg boluses for severe dehydration until pulse, perfusion, and mental status normalize 1, 3
• Avoid loperamide in this presentation—antimotility drugs should not be used when there is abdominal pain, fever, or suspected inflammatory diarrhea due to risk of toxic megacolon 1, 4

Eczema Treatment During Acute Phase

Topical corticosteroids remain the mainstay of eczema therapy, with treatment intensity based on severity and location. 5, 6, 7

• Apply mid-to-high potency topical corticosteroids (triamcinolone 0.1% or betamethasone valerate 0.1%) to inflamed body areas twice daily 5, 6
• Use low-potency corticosteroids (hydrocortisone 2.5%) on the face and intertriginous areas 5, 6
• Add topical calcineurin inhibitors (tacrolimus 0.1% or pimecrolimus 1%) to sensitive areas or as steroid-sparing agents 6, 7
• Implement liberal emollient use and daily bathing with soap-free cleansers as maintenance therapy 6, 7
• Consider oral antihistamines (cetirizine 10 mg daily or hydroxyzine 10-25 mg at bedtime) for pruritus, though evidence for efficacy is limited 1, 6

If Infectious Workup is Negative and Symptoms Persist

Consider empiric treatment for possible IBD if inflammatory markers are elevated and infectious causes excluded. 1

• Start prednisone 40-60 mg daily (or 0.5-1 mg/kg/day) if moderate-to-severe symptoms persist after 2-3 days 1
• Refer urgently to gastroenterology for endoscopic evaluation 1
• Continue aggressive topical therapy for eczema as above 5, 6

Critical Pitfalls to Avoid

• Never use loperamide when inflammatory diarrhea is suspected—it can precipitate toxic megacolon and mask worsening inflammation 1, 4
• Do not dismiss the temporal association of new eczema with GI symptoms—this constellation suggests systemic immune dysregulation requiring investigation 2, 8
• Avoid empiric antibiotics unless dysentery (bloody diarrhea with fever) is present or C. difficile is confirmed 1
• Do not use insoluble fiber (wheat bran) if IBS is later diagnosed, as it exacerbates symptoms; soluble fiber (ispaghula) is preferred 1
• Check for food allergies if symptoms persist—gastrointestinal symptoms in eczema patients are often related to specific food ingestion and are associated with positive skin prick tests 8

Monitoring and Disposition

• Hospital admission is indicated for severe dehydration requiring IV fluids, inability to tolerate oral intake, or signs of severe colitis (≥7 bowel movements daily, peritoneal signs) 1, 3
• Reassess within 24-48 hours if managed outpatient to monitor for progression 1
• Continuous monitoring of hydration status including urine output, vital signs, and mental status 3
• If IBD is confirmed, avoid chronic loperamide use and instead address underlying inflammation with disease-modifying therapy 4