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Complete GP Treatment Guideline: Chronic Diarrhea with Weakness

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1. DEFINITION & RED FLAGS

🚨 Alarm Features — Refer/Investigate Urgently

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2. DIAGNOSTIC FRAMEWORK (Management Algorithm)

Step 1 — Classify by Symptom Pattern

Step 2 — First-Line Investigations (GP Level)

• CBC (anemia → blood loss or nutritional deficiency; eosinophilia → parasites)
• CMP (electrolytes — hypokalemia in secretory diarrhea; albumin — protein loss)
• CRP/ESR (inflammation screen)
• IgA tissue transglutaminase (TTG-IgA) + total IgA → celiac disease
• Thyroid function (hyperthyroidism can cause diarrhea + weakness)
• Iron, folate, B12, vitamin D (malabsorption markers)
• Blood glucose (diabetic diarrhea/autonomic neuropathy)

• Fecal occult blood
• Fecal calprotectin or lactoferrin (sensitivity ~92%/specificity ~82% for inflammatory diarrhea)
• Stool culture, ova & parasites, Giardia and Cryptosporidium antigen (or multiplex PCR)
• Stool fat (Sudan stain — sensitivity 76–94% for steatorrhea)

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3. CAUSES BY MECHANISM (Major Categories)

Secretory Diarrhea

• Stimulant laxatives, chronic ethanol, drugs (olmesartan, metformin, SSRIs, colchicine)
• Hormone-producing tumors (VIPoma, carcinoid, gastrinoma, medullary thyroid cancer)
• Addison's disease, bile acid diarrhea, congenital electrolyte defects

Osmotic Diarrhea

• Lactase deficiency, sorbitol/fructose/FODMAPs, osmotic laxatives (Mg²⁺, PO₄³⁻)

Steatorrheal / Malabsorptive Diarrhea (major cause of weakness)

• Celiac disease (most common in adults — screen all!)
• Pancreatic exocrine insufficiency (stool fat >20 g/day → pancreatic function test)
• Bacterial overgrowth (SIBO), Whipple's disease, Crohn's disease
• Stool fat 14–20 g/day → search for small bowel cause
• Stool fat >20 g/day → assess pancreatic function

Inflammatory Diarrhea (IBD)

• Crohn's disease, ulcerative colitis, microscopic colitis (lymphocytic/collagenous)
• Infectious: Giardia, Entamoeba, C. difficile, tuberculosis

Functional / IBS-D

• Pain aggravated before BM, relieved by BM, urgency, bloating
• Diagnosis of exclusion

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4. TREATMENT BY CAUSE

A. Specific / Curative Treatments

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B. Symptomatic / Empirical Treatments (When Cause Not Identified or as Adjunct)

Antidiarrheal / Antimotility Agents

Stool-Modifying / Adjunctive

• Psyllium (bulk-forming): improves stool consistency; useful with fecal incontinence
• Calcium 1–2 g/day: may reduce stool frequency via unknown mechanism
• Pectin: delays proximal transit; adjunctive
• Probiotics: modest evidence; may help antibiotic-associated and travelers' diarrhea

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5. MANAGEMENT OF WEAKNESS (Complication of Chronic Diarrhea)

A. Fluid & Electrolyte Depletion

• Oral rehydration solution (ORS) — central to management; isotonic solutions preferred
• For sport drinks: adequate for mild cases; WHO-ORS or Pedialyte preferred for moderate
• Potassium replacement: low K⁺ is a hallmark of chronic secretory diarrhea → oral KCl supplements; dietary potassium (bananas, potatoes)
• IV fluids (Ringer's lactate or NS) if oral intake inadequate or severe dehydration

B. Nutritional Deficiencies (Malabsorption)

C. Underlying Disease Causing Weakness

• Celiac disease → GFD corrects all deficiencies
• IBD → treat inflammation; nutritional support
• Adrenal insufficiency → hydrocortisone dramatically reverses weakness
• Hyperthyroidism → antithyroid treatment restores weight and strength
• Malignancy → oncology referral

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6. WHEN TO REFER (Red Line for GP)

• Any alarm feature present
• Diagnosis unclear after initial workup
• Positive fecal calprotectin (>200 µg/g) → IBD workup
• Suspected malabsorption (steatorrhea, weight loss, hypoalbuminemia)
• Persistent diarrhea >4–6 weeks despite empirical treatment
• Colonoscopy/small bowel imaging indicated

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7. GP APPROACH — PRACTICAL FLOWCHART

CHRONIC DIARRHEA (>4 weeks) + WEAKNESS
             │
             ▼
  STEP 1: Alarm features? ──YES──► Urgent colonoscopy / refer GI
             │ NO
             ▼
  STEP 2: Drug review → Stop offending drugs
             │
             ▼
  STEP 3: Exclude infection → Stool cultures, O&P, Giardia Ag, PCR
             │
             ▼
  STEP 4: Blood screen → CBC, CMP, CRP, TTG-IgA, TFTs, B12/folate/Fe, Vit D
          Stool screen → Calprotectin, stool fat, FOBT
             │
             ▼
  STEP 5: Pattern-based diagnosis:
    - IBS-D criteria met, normal bloods → Dietary trial (low-FODMAP), loperamide, rifaximin
    - Celiac suspected → GFD + refer GI
    - Malabsorption signs → Small bowel workup + nutritional replacement
    - Inflammatory signs (high calprotectin/CRP) → Colonoscopy + biopsy
    - Infectious → Targeted antibiotic therapy
             │
             ▼
  STEP 6: Correct Weakness
    - ORS / electrolyte replacement
    - Treat nutritional deficiencies (Fe, B12, folate, Vit D, Mg, Zn)
    - High-protein, low-irritant diet
             │
             ▼
  STEP 7: Empirical antidiarrheal if no diagnosis
    - Loperamide first-line
    - Cholestyramine trial (bile acid diarrhea)
    - Rifaximin trial (SIBO/IBS)
    - Refer if no response in 4–6 weeks

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8. DIETARY ADVICE FOR PATIENTS

• Avoid lactose (dairy) initially as a trial — if improvement, confirm lactase deficiency
• Trial low-FODMAP diet for IBS-D
• Avoid sorbitol (sugar-free gum, candies), fructose (excess fruit juice), alcohol, caffeine
• Gluten-free trial only after celiac serology — do NOT start before blood test
• Small, frequent meals; avoid high-fat meals if steatorrhea suspected
• Maintain adequate fluid intake (minimum 2 L/day); use ORS if significant ongoing losses

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9. MONITORING

• Review in 2–4 weeks after initial treatment
• Repeat CBC, electrolytes, albumin at 6–8 weeks if malabsorption or significant weakness
• Track weight, stool frequency (Bristol Stool Scale), and energy levels
• If persistent: escalate investigations (colonoscopy, CT enterography, hydrogen breath test)

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Complete GP Treatment Guideline: Common Skin Diseases

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PART 1 — ECZEMA / DERMATITIS

1.1 Atopic Dermatitis (Eczema)

Clinical Features

• Infants: face, scalp, extensor surfaces
• Children/adults: flexural surfaces (antecubital/popliteal fossae), neck, wrists
• Intense pruritus, xerosis, lichenification in chronic disease

Treatment — Stepwise Approach

• Apply emollient (aqueous cream, petroleum jelly, ceramide-based moisturizer) generously, at least twice daily, especially after bathing
• Lukewarm (not hot) baths; pat dry — do not rub
• Avoid soaps, detergents, wool, synthetic fabrics
• Cotton clothing; trim fingernails short

Apply once or twice daily during flares. Use lowest effective potency. "Weekend therapy" (twice weekly) maintains remission. Never stop abruptly on potent steroids.

• Tacrolimus 0.03% / 0.1% ointment — moderate-to-severe AD, face/eyelids, skin folds
• Pimecrolimus 1% cream — mild-moderate AD
• Apply twice daily; may cause initial burning/stinging (improves in 1 week)
• Preferred for long-term maintenance on sensitive areas

• Crisaborole 2% ointment — mild-moderate AD; twice daily; minimal side effects

• Dupilumab (IL-4/IL-13 inhibitor) — 300 mg SC every 2 weeks; first-line biologic; safe long-term
• Cyclosporine 2.5–5 mg/kg/day — rapid effect; short-term use (3–12 months); monitor BP/renal function
• Methotrexate 7.5–25 mg/week — folate supplementation required; LFT monitoring
• Azathioprine 1–3 mg/kg/day — TPMT test before starting
• Oral corticosteroids — short courses only (1–2 weeks) for severe flares; avoid long-term use
• JAK inhibitors (upadacitinib, abrocitinib) — newer; specialist-initiated

• Short courses of topical mupirocin or fusidic acid for localised infection
• Oral flucloxacillin 500 mg QID × 7 days for infected eczema
• Bleach baths (0.005% sodium hypochlorite) twice weekly may reduce colonization

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1.2 Contact Dermatitis

Treatment

• Identify and remove trigger — patch testing for ACD
• Emollients and barrier creams (especially for ICD)
• TCS (as above) for active dermatitis — moderate-to-potent based on site
• Tacrolimus for facial/eyelid ACD
• Avoid relevant allergens lifelong (ACD)
• Protective gloves (vinyl preferred over rubber for latex allergy)
• Refer for patch testing if source unclear

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1.3 Seborrhoeic Dermatitis

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PART 2 — PSORIASIS

Clinical Features

• Well-demarcated, silvery-scaly erythematous plaques
• Sites: scalp, extensor surfaces (elbows, knees), lower back, nails
• Auspitz sign (pinpoint bleeding on scale removal)
• Nail changes: pitting, onycholysis, oil-drop sign

Treatment — by Severity

Biologics in GP: GP role is to screen for contraindications (TB, active infection, demyelinating disease, CHF), manage comorbidities, and monitor for side effects.

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PART 3 — ACNE VULGARIS

Classification & Treatment

Key Agents

• Retinoids: Tretinoin 0.025–0.1% cream/gel; adapalene 0.1–0.3% gel; tazarotene 0.1% — normalize follicular keratinization; apply nightly; photosensitizing — use sunscreen
• Benzoyl peroxide (BPO) 2.5–10%: antibacterial; reduces antibiotic resistance; leave-on or wash-off; can bleach fabrics
• Topical antibiotics: Clindamycin 1% or erythromycin 2% — always combine with BPO to prevent resistance; do not use as monotherapy
• Dapsone 5–7.5% gel: useful especially in adult females; anti-inflammatory
• Azelaic acid 15–20%: anti-inflammatory, comedolytic, hyperpigmentation; safe in pregnancy
• Clascoterone 1% cream: androgen receptor antagonist; safe in males

• Doxycycline 50–100 mg BD (first-line) or 40 mg MR (subantimicrobial)
• Minocycline 50–100 mg BD — avoid in pregnancy; autoimmune risk with long use
• Lymecycline 408 mg/day (UK common)
• Trimethoprim 300 mg BD — second-line

• Combined oral contraceptive pill (ethinyloestradiol + norgestimate/drospirenone/cyproterone acetate) — effective for hormonal acne; 3–6 months for effect
• Spironolactone 50–150 mg/day — off-label; anti-androgen; monitor K⁺

• 0.5–1 mg/kg/day × 4–6 months (cumulative dose ~120–150 mg/kg)
• Highly teratogenic — REMS programme (iPLEDGE); two forms of contraception
• Monitor LFTs, lipids, CBC monthly
• Side effects: xerosis, cheilitis, myalgia, mood changes (monitor)

Patient Advice

• Do not squeeze or pick lesions
• Sunscreen daily (non-comedogenic, SPF 30+)
• Diary of diet if hormonal pattern suspected
• Expect 6–8 weeks before visible improvement

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PART 4 — BACTERIAL SKIN INFECTIONS

4.1 Impetigo

4.2 Cellulitis / Erysipelas

• Elevate affected limb; mark margin with pen to monitor spread
• Treat underlying entry point (tinea pedis, eczema)
• Recurrent cellulitis (≥2/year): prophylactic penicillin V 250 mg BD long-term

4.3 Folliculitis

• Mild/superficial: antiseptic wash (chlorhexidine 4%); topical mupirocin or fusidic acid
• Moderate: oral flucloxacillin 500 mg QID × 7 days
• Hot tub folliculitis: usually self-limiting; oral ciprofloxacin if severe
• Decolonisation for recurrent: nasal mupirocin + chlorhexidine washes × 5 days

4.4 Furuncle (Boil) / Carbuncle

• Incision and drainage — primary treatment; send pus for culture
• Oral antibiotics if surrounding cellulitis: flucloxacillin 500 mg QID × 7 days
• Carbuncle / multiple boils: consider MRSA; screen household contacts
• Decolonisation protocol if recurrent

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PART 5 — FUNGAL SKIN INFECTIONS

5.1 Dermatophytosis (Tinea)

Confirm with KOH preparation if diagnosis uncertain before starting oral antifungals.

5.2 Candidiasis

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PART 6 — VIRAL SKIN INFECTIONS

6.1 Herpes Simplex (HSV-1 / HSV-2)

6.2 Herpes Zoster (Shingles)

• Antivirals (start within 72 hours of rash onset — or at any time if new vesicles forming):
  • Valaciclovir 1 g TID × 7 days (preferred)
  • Aciclovir 800 mg 5×/day × 7 days
  • Famciclovir 250 mg TID × 7 days
• Indications to always treat: age >50, ophthalmic zoster, ear involvement (Ramsay Hunt), moderate-severe pain, immunosuppressed
• Pain management: paracetamol ± ibuprofen; amitriptyline 10–25 mg nocte early (prevents post-herpetic neuralgia); gabapentin 300 mg TID for PHN
• Ophthalmic zoster: urgent ophthalmology referral + oral valaciclovir
• Vaccination: recombinant zoster vaccine (Shingrix®) — two doses; age ≥50

6.3 Warts (Human Papillomavirus)

6.4 Molluscum Contagiosum

• Usually self-limiting in immunocompetent children (6–18 months)
• Active treatment (for adults, immunosuppressed, or extensive):
  • Cryotherapy; podophyllotoxin 0.5%; potassium hydroxide 5–10% solution
  • Imiquimod 5% cream (off-label)
  • Curettage under EMLA cream

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PART 7 — INFESTATIONS

7.1 Scabies (Sarcoptes scabiei)

• Treat all household/close contacts simultaneously
• Wash clothing/bedding on 60°C on day of treatment; bag items that can't be washed for 72 hours
• Post-scabetic itch (immune reaction) can persist 4–6 weeks — treat with crotamiton or mild TCS; does not mean treatment failure
• Crusted scabies: combined oral ivermectin + topical permethrin; contact isolation

7.2 Head Lice (Pediculus capitis)

• Dimeticone 4% lotion (Hedrin®) — physical insecticide; apply 8 hours or overnight; repeat in 7 days (first-line in UK)
• Malathion 0.5% — leave 12 hours; repeat in 7 days (if dimeticone fails)
• Wet combing (Bug Buster method) — every 3–4 days for 2 weeks; alternative to insecticides
• Permethrin 1% rinse — alternative
• Treat all household members simultaneously

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PART 8 — URTICARIA & ANGIOEDEMA

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PART 9 — ROSACEA

• Doxycycline 40 mg MR/day (subantimicrobial dose; Oracea®) × 12–16 weeks — preferred
• Doxycycline 50–100 mg BD × 8–12 weeks

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PART 10 — PSORIASIFORM & PAPULOSQUAMOUS CONDITIONS

10.1 Pityriasis Rosea

• Self-limiting viral exanthem; herald patch → widespread fir-tree rash
• Reassure; emollients; mild TCS for itch; usually resolves in 6–8 weeks
• Oral aciclovir (800 mg 5×/day × 7 days) if very severe or immunosuppressed (HHV-6/7 linked)

10.2 Lichen Planus

• Pruritic, purple, polygonal papules; Wickham's striae; oral/genital involvement
• Topical: potent TCS (clobetasol) for skin; triamcinolone in Orabase® for oral LP
• Systemic: prednisolone 30 mg/day × 2 weeks taper for widespread/erosive disease
• Acitretin for severe/recalcitrant; refer if oral erosive or nail LP

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PART 11 — HYPERPIGMENTATION & HYPOPIGMENTATION

11.1 Melasma

• Facial hyperpigmentation; triggered by sun, OCP, pregnancy
• First-line: triple combination — hydroquinone 4% + tretinoin 0.025% + hydrocortisone 1% (Tri-Luma®) nightly × 8 weeks
• SPF 50+ sunscreen every morning (non-negotiable)
• Azelaic acid 20% or kojic acid as alternatives
• Stop OCP if causative; treat after delivery in pregnancy-related

11.2 Vitiligo

• Autoimmune depigmentation; depressed psychological impact
• Narrow-band UVB phototherapy (most effective; 3×/week × 6 months)
• Topical tacrolimus 0.1% BD for face/sensitive areas
• Potent TCS on non-facial/non-flexural areas
• Ruxolitinib 1.5% cream (JAK1/2 inhibitor) — recently approved; twice daily
• Cosmetic camouflage (Dermablend®, Covermark®); sunscreen to prevent burns in depigmented areas

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PART 12 — SKIN CANCERS — RED FLAGS FOR GP

12.1 Basal Cell Carcinoma (BCC)

• Pearlescent/rolled-edge nodule; telangiectasia; central ulceration ("rodent ulcer")
• Refer to dermatology — surgical excision (1st line); Mohs micrographic surgery for high-risk sites
• Superficial BCC: imiquimod 5% cream 5×/week × 6 weeks; photodynamic therapy (PDT)

12.2 Squamous Cell Carcinoma (SCC)

• Ulcerated keratotic papule/plaque; crusted; friable; sun-exposed sites
• Urgent 2-week wait referral — surgical excision ± radiotherapy; immunosuppressed patients at very high risk

12.3 Melanoma — ABCDE Rule

• Asymmetry, Border irregularity, Colour variation, Diameter >6mm, Evolving
• Urgent 2-week wait referral — any suspicious lesion
• GP role: do NOT attempt biopsy; photograph and refer promptly
• Dermoscopy if trained; apply Rule of Ugly Duckling

12.4 Actinic Keratosis (Pre-malignant)

• Rough, scaly, red lesions on sun-exposed skin; potential SCC precursor
• Cryotherapy (liquid nitrogen): 5–10 seconds per lesion; 2–4 week interval
• Fluorouracil 5% cream (Efudix®): BD × 3–4 weeks; expected brisk inflammatory reaction
• Imiquimod 5%: 3×/week × 4 weeks; field treatment
• Diclofenac 3% gel (Solaraze®): BD × 90 days; milder reaction; for large fields
• Photodynamic therapy (PDT): 1–2 sessions; for widespread field disease

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PART 13 — WOUND CARE & ULCERS AT GP LEVEL

Venous Leg Ulcers

• ABPI (ankle-brachial pressure index) before compression — exclude arterial disease
• Compression therapy (4-layer bandaging; 40 mmHg) — cornerstone of treatment
• Wound cleansing: saline or potable water
• Dressings: non-adherent, moisture-retaining — hydrocolloid, foam, alginate based on exudate
• Treat infection: topical cadexomer iodine; oral antibiotics only if systemic signs
• Pentoxifylline 400 mg TID (adjunct); aspirin 300 mg/day (adjunct)

Pressure Ulcers

• Staging I–IV; Grade III/IV refer to tissue viability / specialist nursing
• Relieve pressure (reposition q2h; specialist mattress)
• Debridement; appropriate dressings; nutritional support (protein, vitamin C, zinc)

Diabetic Foot Ulcers

• Refer to multidisciplinary diabetic foot team
• Debridement; off-loading (total contact cast)
• Antibiotics guided by depth and culture; empirical amoxicillin-clavulanate for mild infection

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PART 14 — WHEN TO REFER FROM GP

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PART 15 — TOPICAL CORTICOSTEROID POTENCY GUIDE (Quick Reference)

Side effects of TCS: skin atrophy, striae, telangiectasia, hypopigmentation, tachyphylaxis, adrenal suppression (with very potent/extensive use), perioral dermatitis (face). Use minimum effective potency.

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Disclaimer: This is a clinical reference for GP-level management. Always individualise treatment, check current BNF/local formulary for dosing, and follow local guidelines for antimicrobial stewardship.Your credits are exhausted. Your daily credits reset tomorrow, or you can purchase a top-up for more.