What is the diagnosis and treatment for a patient with a history of liver disease and potential exposure to arsenic, presenting with crusted scaly lesions on the scalp and left leg?

Diagnosis and Treatment of Crusted Scaly Scalp and Leg Lesions in a Patient with Liver Disease and Arsenic Exposure

Primary Diagnosis

The most likely diagnosis is arsenical keratosis with underlying chronic arsenic-induced liver disease, requiring immediate cessation of arsenic exposure, dermatologic management of skin lesions, and hepatologic evaluation for potential cirrhosis or portal hypertension. 1, 2

Differential Diagnosis to Consider

Arsenical Skin Changes (Most Likely)

• Chronic arsenic ingestion causes characteristic crusted, scaly skin lesions (arsenical keratoses) that typically appear on palms, soles, and can occur on scalp and extremities 1
• These lesions are well-documented in patients with chronic arsenicosis and often accompany liver disease 1, 2
• The combination of liver disease history with crusted scaly lesions strongly suggests chronic arsenic toxicity 1

Psoriasis (Alternative Consideration)

• Thick psoriatic plaques can present as crusted scaly lesions on scalp and extremities 3
• However, psoriasis typically presents with hundreds of lesions involving larger body surface area (not just scalp and one leg lesion) 3
• The presence of liver disease and arsenic exposure makes arsenical keratosis more likely 1

Erosive Pustular Dermatosis of Scalp (Less Likely)

• This condition presents with pustular lesions, erosions, and crusts on scalp in elderly patients 4
• Autoimmune hepatitis is an associated condition with erosive pustular dermatosis 4
• However, this typically affects only the scalp and is not associated with leg lesions 4

Critical Diagnostic Workup

Immediate Skin Assessment

• Examine for additional arsenical skin changes including hyperpigmentation, palmar/plantar keratoses, and Bowen's disease (intraepithelmal carcinoma) 1
• Document distribution and characteristics of all skin lesions
• Consider skin biopsy if diagnosis remains uncertain, though arsenical keratoses have characteristic clinical appearance 1

Arsenic Exposure Confirmation

• Obtain detailed history of water source, occupational exposures, and traditional medicine use 2
• Measure 24-hour urinary arsenic levels (elevated >50 μg/L suggests chronic exposure) 2
• Consider hair and nail analysis for chronic exposure assessment 1

Hepatic Evaluation (Critical Given Liver Disease History)

• Hepatomegaly is present in 76.6% of patients with chronic arsenicosis 2
• Noncirrhotic portal fibrosis is the predominant lesion (91.3% of cases) in arsenic-induced liver disease 2
• Obtain complete liver function tests including AST, ALT, alkaline phosphatase, bilirubin, albumin, and globulin 5, 2
• Check for elevated globulin levels, which occur in chronic arsenicosis 2
• Perform abdominal ultrasound to assess for hepatomegaly, splenomegaly, portal hypertension, and exclude hepatocellular carcinoma 3
• Screen for esophageal varices with upper endoscopy if portal hypertension is suspected 3, 2

Malignancy Screening (Essential)

• Chronic arsenic exposure increases risk of hepatocellular carcinoma, even in non-cirrhotic livers 1
• Measure serum alpha-fetoprotein (AFP) to screen for HCC 3
• Perform multiphasic contrast-enhanced CT or MRI if any liver mass is detected or AFP is elevated 6
• Arsenical keratoses can transform into squamous cell carcinoma or Bowen's disease 1

Exclude Competing Diagnoses

• Rule out viral hepatitis (HBsAg, anti-HCV) as these can coexist with arsenic toxicity 2
• Consider autoimmune hepatitis if ANA positive and transaminases markedly elevated 7
• Exclude Wilson's disease if patient is young (<40 years) with unexplained liver disease 3

Treatment Algorithm

Immediate Interventions

Step 1: Eliminate Arsenic Exposure

• Identify and remove source of arsenic exposure immediately 1, 2
• Provide arsenic-free water supply 2
• This is the single most important intervention to prevent disease progression 2

Step 2: Hepatoprotective Therapy

• Consider N-acetylcysteine (NAC) supplementation, which has been shown to abrogate arsenic-induced liver injury through glutathione-dependent mechanisms 8
• NAC prevents mitochondrial oxidative stress and apoptotic liver cell death in arsenic toxicity 8

Step 3: Dermatologic Management

• For arsenical keratoses: topical keratolytics (salicylic acid, urea preparations)
• Monitor closely for malignant transformation to squamous cell carcinoma 1
• If lesions are suspicious for malignancy, perform biopsy 1

Management of Liver Disease Complications

Portal Hypertension Management

• If esophageal varices develop, initiate non-selective beta-blockers for primary prophylaxis 3
• Monitor for ascites, hepatic encephalopathy, and variceal bleeding 3, 5

Hepatocellular Carcinoma Surveillance

• Perform abdominal ultrasound every 6 months for HCC surveillance 3
• Patients with arsenic-induced liver disease require lifelong HCC surveillance even without cirrhosis 1

Liver Transplantation Consideration

• If patient develops decompensated cirrhosis or HCC within Milan criteria, refer for liver transplantation evaluation 3
• Arsenic-induced liver disease is a valid indication for transplantation 3

Long-Term Monitoring

Follow-Up Schedule

• Cohort studies show that even after switching to arsenic-free water, patients can develop esophageal varices and elevated globulin over 2-12 years 2
• Monitor liver function tests every 3-6 months indefinitely 2
• Continue HCC surveillance with ultrasound ± AFP every 6 months 3
• Annual dermatologic examination for skin cancer screening 1

Critical Pitfalls to Avoid

• Do not assume liver disease is "cryptogenic" without investigating arsenic exposure history 1
• Do not discontinue HCC surveillance even if liver function normalizes, as HCC can develop in non-cirrhotic arsenic-exposed livers 1
• Do not ignore single skin lesions as benign—arsenical keratoses require close monitoring for malignant transformation 1
• Do not delay removal of arsenic source while awaiting confirmatory testing 2
• Do not assume disease will resolve completely after arsenic cessation—portal hypertension can progress despite removal of exposure 2