Clinical Presentations of Arsenic Toxicity
Arsenic toxicity presents with distinct patterns depending on whether exposure is acute or chronic, with acute poisoning manifesting primarily as severe gastrointestinal symptoms followed by multi-organ dysfunction, while chronic exposure produces characteristic dermatologic changes, peripheral neuropathy, and increased cancer risk. 1, 2
Acute Arsenic Poisoning
Gastrointestinal Manifestations (Initial Presentation)
- Severe nausea and vomiting occur as the earliest symptoms 3
- Abdominal pain with severe, cholera-like diarrhea develops rapidly 3
- Metallic taste in the mouth may be reported 4
Neurological Complications
- Toxic delirium and encephalopathy can develop in severe cases 4
- Altered mental status including sleepiness and seizures in life-threatening presentations 2
- Peripheral neuropathy may emerge even in acute settings 3
Cardiovascular and Respiratory Effects
- Difficulty breathing indicates severe toxicity requiring immediate intervention 2
- Cardiovascular collapse can occur in severe acute poisoning 5
Chronic Arsenic Toxicity (Arsenicosis)
Pathognomonic Dermatologic Features
- Hyperpigmentation with characteristic "raindrop" pattern is highly specific for chronic arsenic exposure 1, 6
- Palmar and plantar hyperkeratosis (thickening of skin on hands and feet) represents the hallmark finding 4, 6
- Mee's lines (transverse white lines on fingernails) may appear 4
Systemic Manifestations
Hematologic:
Hepatic:
- Non-cirrhotic portal fibrosis leading to portal hypertension 4, 6
- Bleeding esophageal varices with splenomegaly and hypersplenism 4
- Hepatomegaly without cirrhosis 6
Pulmonary:
- Chronic bronchitis and chronic obstructive pulmonary disease 6
- Bronchiectasis from prolonged exposure 6
Neurological:
- Peripheral neuropathy with sensory and motor deficits 4, 6
- Polyneuropathy affecting distal extremities 6
Cardiovascular:
- "Blackfoot disease" (peripheral vascular disease with gangrene) historically associated with arsenic-contaminated water in Taiwan 4
- Raynaud's phenomenon and acrocyanosis 4
- Hypertension and ischemic heart disease 6
Metabolic:
Constitutional:
- Generalized weakness and fatigue 6
Malignancies Associated with Chronic Exposure
The most critical long-term consequence is increased cancer risk across multiple organ systems: 1, 2
- Skin cancer (basal cell and squamous cell carcinoma) - most common and detectable early with surveillance 6
- Lung cancer with significantly elevated mortality rates 5
- Bladder cancer strongly associated with chronic exposure 6, 5
- Liver, kidney, and colon cancers also demonstrate increased incidence 5
Critical Diagnostic Distinctions
Inorganic vs. Organic Arsenic
It is essential to distinguish between inorganic and organic arsenic exposure, as this fundamentally changes clinical interpretation: 1
- Inorganic arsenic (from contaminated water, industrial exposure) is highly toxic and carcinogenic 2
- Organic arsenic (from seafood consumption) is relatively non-toxic and does not cause arsenicosis 1
- Seafood consumption can elevate urinary arsenic levels without clinical toxicity, potentially confounding diagnosis 7
Common Clinical Pitfalls
Do not dismiss elevated urinary arsenic in patients with high seafood consumption - while organic arsenic from seafood is non-toxic, it can mask concurrent inorganic arsenic exposure 7
Early skin cancers in chronic arsenicosis are curable if detected - regular dermatologic surveillance is critical for patients with known chronic exposure 6
Peripheral neuropathy from arsenic can be mistaken for other causes - always obtain exposure history in patients with unexplained neuropathy, particularly in endemic areas 4, 6
Chronic exposure requires long-term cancer surveillance even after exposure cessation, as malignancies can develop years later 2