• Gastro-intestinal mucosa. Burning epigastric pain, vomiting after every swallow, rice-water diarrhoea, tenesmus, collapse, with restlessness and anguish; thirst for small sips. See Stomach/Abdomen/Rectum. [Hering], [Allen], [Nash]
• Respiratory tract. Asthma after midnight (1–2 a.m.) with fear, restlessness, cold sweat, worse lying, better sitting bent forward and warmth; hay fever, fetid bronchitis. See Respiration/Chest. [Clarke], [Boger]
• Skin & appendages. Burning, excoriating eruptions, eczema/psoriasis, ulcerations with black bases, desquamation, urticaria, herpes zoster neuralgia (burning); better hot applications though patient is chilly. See Skin. [Hering], [Allen]
• Kidney & serous membranes. Albuminuria, oedema, nephritis, anasarca; peritonitis/pleuritis with burning pain and prostration. See Urinary/Chest/Abdomen. [Clarke], [Farrington]
• Cardio-vascular. Small, rapid pulse, angor animi, collapse, arrhythmia from exhaustion; post-infectious asthenia. See Heart/Generalities. [Kent], [Allen]
• Mind–autonomic axis. Anxiety for life, fear of being alone, compulsive neatness, mistrust, restlessness—cannot lie in one place; hypochondriasis about health with suspiciousness and chilliness. See Mind. [Kent], [Tyler]
• Naso-pharyngeal & allergic. Acrid, watery coryza that excoriates, sneezing, burning nostrils/lips; hay asthma. See Nose/Face/Respiration. [Clarke], [Allen]
• Cancer cachexia & ulcerations. Fetor, burning pains (heat relieves), cadaveric odours, offensive discharges, restlessness—palliative sphere. See Skin/Generalities. [Hughes], [Clarke]

• Warmth in general; hot applications to burning pains. [Hering], [Allen]
• Sips of warm drinks (frequent, small quantities). [Clarke]
• Company and reassurance (fear of being alone). [Kent]
• Sitting up or leaning forward (asthma, cardiac oppression). [Boger]
• Head high; propped in bed. [Clarke]
• Dry, warm room; well-covered (despite burning pains). [Hering]
• Slow, measured movements—order calms. [Kent]
• External heat to chest/abdomen during colic/bronchial spasm. [Farrington]
• Gentle, frequent nourishment (warm), not large meals. [Clarke]
• Meticulous arrangement of surroundings (reduces anxiety). [Tyler]
• Expulsion of discharges (vomit/stool) may briefly ease the anguish. [Allen]
• After midnight once the paroxysm passes (relative). [Boger]

• After midnight (about 1–2 a.m.), towards 3 a.m. (asthma, diarrhoea, anxiety). [Kent], [Boger]
• Cold—air, food, drinks; getting chilled; cold damp. [Hering]
• Exertion, ascending, even slight effort (exhaustion, palpitation). [Allen]
• Rest (must move from place to place in bed); lying supine (oppression). [Kent]
• Eating/drinking—even a little aggravates nausea/vomiting. [Allen]
• Seawater, fish, decayed foods (food poisoning theme). [Clarke]
• Open air when chilly; drafts on head/chest. [Hering]
• Alone; darkness; noise; after fright/shock. [Tyler]
• Periodicity—every other day, autumn, malarial marsh. [Boger]
• Suppression of skin/secretions (eczema, sweat) → internal illness. [Clarke]
• Tobacco smoke in respiratory types; ice-cold drinks in gastritis. [Allen]
• Morning weakness and noon collapse in cachectic states. [Farrington]

The Arsenicum psyche is a crucible of fear and order. The patient is anguished, restless, and suspicious, haunted by the certainty of impending death, yet fights terror with fastidious control—arranging, cleaning, counting, seeking reassurance. Fear of being alone is intense; at night he wakes after midnight, compelled to change places, sits up gasping with palpitations, icy extremities, and internal burning. He is chilly, pernickety, dependent, yet critical; intolerance of disorder mirrors internal disintegration. Miserly, anxious about health and money, he may hide symptoms out of fear. In children: restless fretfulness, refuses to be put down, burning diarrhoea, lips excoriated. Differs from Acon. (sudden panic with heat, not meticulous), Carb-veg. (despair of life with air-hunger and collapse but desires fanning, not heat), Phos. (open, sympathetic, thirsty for cold drinks), and Nux-v. (irritable executive, not fearful dependence). Case: a man with nightly 1 a.m. asthma, insists on extra blankets and hot tea, cannot stay in one position, certain he will die—Ars. 200C restored sleep and eased breath within nights. [Kent], [Hering], [Allen], [Clarke], [Tyler], [Nash]

Burning frontal headache with cold scalp, worse after midnight, better heat. Neuralgia with burning like fire, yet external heat relieves—a paradox hallmark. Vertigo on rising with faintness; face pale, pinched, cadaveric odour from mouth in gastric crises. Occipital chill with facial heat; cold sweat on forehead with anxiety. Distinguish from Bell. (throbbing heat), Glon. (bursting, pulsating), Carb-veg. (collapse with air-hunger). [Allen], [Hering], [Clarke]

Burning, acrid lachrymation excoriating lids; photophobia, oedematous lids, blepharitis with scales; ulcerative keratitis (edges grey), burning better warmth. Nocturnal aggravation; tears hot. Compare Euph. (bland tears, acrid nasal discharge), Sulph. (burning but less chilliness). [Hering], [Allen], [Clarke]

Otalgia with burning, oedematous auricles, thin acrid discharge, noises with anxiety; eruption behind ears excoriating. [Allen], [Clarke]

Acrid, watery coryza that scalds the nostrils and upper lip; burning within nose, obstruction at night; sneezing in cold air; hay fever—sneezes, watery excoriating flow, burning, better heat. Epistaxis with exhaustion. Differs All-c. (profuse watery discharge but cold not desired), Puls. (bland coryza, open air better). [Clarke], [Hering], [Allen]

Pale, anxious, pinched, blue rings around eyes; lips cracked and burning, corners excoriated; facial neuralgia burning, heat relieves. Oedema of eyelids, malar puffiness; cadaveric odour in severe gastroenteritis. [Hering], [Allen]

Burning in mouth and tongue; ulcers with burning edges, offensive breath; saliva scant or foetid; thirst for frequent small sips. Taste bitter/metallic; intolerance of cold water (vomits); wants hot water. [Allen], [Clarke]

Toothache burning, worse cold air, better heat; gums bleed and recede, ulcerate with foetor; stitching pains at night aggravating anxiety. [Allen], [Hering]

Burning from fauces to stomach, swallowing hot drinks relieves; thin, acrid mucus excoriates; oedematous uvula; angina with great prostration. Worse after midnight, from cold air/drinks. [Clarke], [Hering]

Cardinal sphere. Intense burning at epigastrium, better hot applications and hot drinks, yet patient is chilly; nausea and retching after every swallow, vomiting of fluids as soon as taken, gastralgia with anguish, faintness, cold sweat; great thirst but for frequent small sips. Food poisoning (tainted meats, fish, ice-cream): vomiting, diarrhoea, collapse with restlessness—a classic Ars. picture. Compare Ipec. (constant nausea without prostration), Nux-v. (gastritis from stimulants, wants warmth but anger not fear), Phos. (burning but craves cold drinks that are vomited when warm). [Hering], [Allen], [Nash], [Farrington], [Clarke]

Burning colic, soreness, tympany, stitching in hypochondria; liver tender, spleen enlarged in malarial types; peritonitis with burning and collapse—patient rolls, then sits up (restless). Ascites with anasarca in nephritic cachexia. Worse after midnight, from cold, after fruits/ice. [Allen], [Clarke], [Boger]

Scanty, albuminous urine, burning in urethra, oedema, nephritis; nocturnal frequency with anxiety; tenesmus vesicae with small, hot emissions. Enuresis in anxious, chilly children during fevers. [Clarke], [Allen]

Diarrhoea—watery, offensive, often “rice-water”; stools burn and excoriate, driving patient from bed after midnight; tenesmus with prostration; haemorrhoids burn, bleed, excoriate. Cholera and traveller’s diarrhoea prototypes. Compare Verat. (copious vomiting/diarrhoea with cold sweat on forehead, wants to be covered), Pod. (painless profuse morning stool), Aloe (gush, incontinence). [Nash], [Allen], [Hering], [Farrington]

Sexual desire low with fear, exhaustion; burning urethral discharge; oedema of scrotum in nephritic states; herpetic eruptions burning, better heat. [Allen], [Hering]

Menses early, profuse, exhausting, burning uterine pain; lochia foetid; leucorrhoea acrid, excoriating. Threatened miscarriage with great anxiety and prostration. Climacteric flushes with restlessness and fear. Compare Sep. (bearing-down, indifference), Puls. (mild, amel. cool air). [Clarke], [Hering]

Short, anxious, worse lying, after midnight; must sit up, throws off bedclothes only to demand warmth by heaters/blankets—contradictory craving for warmth but intolerance of uncovering is consistent; asphyxial fear. [Boger], [Kent]

Palpitation from least effort, pulse small, rapid, angor animi; collapse with cold sweat and icy extremities. Endocarditis/pericarditis with burning, stitching and great weakness. Compare Acon. (sudden fear with heat), Carb-veg. (air hunger, wants fanning). [Allen], [Kent]

Burning pains in chest, better heat, asthma about 1–2 a.m.—must sit up, leans forward, chilly, anxious, wants small sips of hot water; cough dry, exhausting, expectoration scant and foetid if any; oedema of lungs in cardiac/renal states. Pleurodynia burning, dyspnoea from slightest exertion. [Boger], [Clarke], [Allen]

Burning between shoulders, coldness of back with internal heat; weakness lumbar, cannot stand long; restless, changes position constantly. [Allen], [Hering]

Icy cold hands and feet, oedema, burning soles (wants them near heat), night cramps in calves, trembling from weakness, numbness; ulcerations with black bases on legs, foetid discharges. Raynaud-like pallor and burning on re-warming. [Hering], [Allen], [Clarke]

Dry, scaly eruptions, psoriasis with burning, eczema that weeps and excoriates, urticaria burning, herpes zoster with post-herpetic burning neuralgia (heat relieves); ulcers: indurated edges, black base, offensive, burning, worse after midnight, better heat. Pruritus worse warmth of bed but soothed by heat applied—paradox of Arsenic’s burning-needs-heat. [Hering], [Allen], [Clarke]

Sleepless from anxiety and fear, wakes after midnight with oppression, must sit up, change place; dreams of thieves, fire, death, startles, cannot lie long in one spot. Short naps with jerks, unrefreshing; dreads the night. At last falls asleep towards morning, exhausted. [Kent], [Allen], [Hering]

Of death, burglars, fires, business calamities; pursuit, suffocation, falling; wake in terror, seeking light and company. [Allen], [Tyler]

Chilliness marked, wants warmth, shivers on least uncovering; heat with burning pains but external coldness; thirst for frequent small sips; sweat offensive and exhausting, often after midnight; intermittent fevers with periodicity, oedematous face, great prostration. [Hering], [Clarke], [Boger]

Chill: worse after midnight, from cold air, with anxiety. Heat: burning, internal, seeks external heat. Sweat: fetid, stains linen, without relief; cold sweat in collapse. [Allen], [Hering]

Great thirst for frequent small quantities, especially warm drinks. Desire: hot drinks, sometimes coffee; acid things may disagree; aversion to cold water (vomits). Worse from ice-cream, fruits, fish, decayed foods, cold drinks. Hunger with rapid satiety in chronic states. [Hering], [Allen], [Clarke]

Burning pains better by heat, anguish with unceasing restlessness, and rapid prostration define Arsenicum. Chilly, wants warmth, thirsts in sips, worse after midnight, from cold, from exertion, from damp, from spoiled food. Fetor pervades: breath, stools, ulcers, sweat. Periodicity (malarial, asthmatic) and oedema point to capillary and serous involvement. Neat, meticulous, fearful, the Arsenicum patient holds life together by order while entropy gnaws within. [Hahnemann], [Hering], [Allen], [Clarke], [Kent], [Boger], [Boericke], [Farrington], [Phatak], [Tyler], [Nash]

Acute gastro-enteritis / food poisoning

• Verat-alb. Copious vomiting/diarrhoea with cold sweat on forehead, craves cold drinks, wants to be covered; Arsenicum thirsts in sips and wants heat. [Nash]
• Ipec. Persistent nausea with little relief by vomiting, clean tongue; less fear/anguish. [Farrington]
• Nux-v. Gastritis from excess, irritable, craves warmth, but no fear of death or sips keynote. [Kent]
• Ant-crud. White-coated tongue, gastric distension, less collapse. [Clarke]

Asthma after midnight

• Samb. Children, suffocates after midnight, sweats, but no thirst or burning better heat. [Hering]
• Carb-veg. Wants to be fanned, air hunger, coldness with indifference; Ars. has fear + heat-seeking. [Clarke]
• Kali-carb. 2–3 a.m. asthma with back stitching, less fear. [Boger]
• Phos. Burning chest, thirst for cold, open, affectionate temperament. [Farrington]

Skin—burning, excoriating eruptions

• Sulph. Burning/itching, but wants open air, uncovering, morning heat; Ars. chilly and exacting. [Kent]
• Rhus-t. Burning vesicles with restlessness, but better motion and hot bathing with damp cold causation; mental picture different. [Clarke]
• Canth. Burning with smarting urine and vesication, less anxiety/restlessness. [Allen]

Ulcers with fetor

• Sec. Thin, cold, wants uncovering, dry gangrene; Ars. desires heat and is orderly, anxious. [Clarke]
• Merc. Profuse saliva, sweat, worse night, wet tongue, less relief from heat. [Hering]

Nephritis / albuminuria

• Apis. Puffy oedema with stinging, worse heat, better cold (opposite Ars.). [Clarke]
• Canth. Burning urine with tenesmus; less general fear/collapse. [Allen]

Fever with collapse

• Carb-veg. Air hunger, wants fanning, despair; Ars. seeks heat, sips warm fluids with anxious orderliness. [Kent]
• Gelsem. Prostration with drowsy stupor, no anguish; Ars. is keenly anxious. [Tyler]

Cancer pain palliation

• Conium. Stony induration, less burning; calm, not anxious. [Farrington]
• Lach. Left → right, loquacity, heat intolerance; Ars. heat-seeking, neat. [Boger]

Hay fever

• All-c. Profuse watery discharge, nose runs like a tap; Ars. acrid excoriation with burning and chilliness, wants warmth. [Clarke]
• Sabad. Paroxysmal sneezing with cold shivers; mental picture not Arsenical. [Allen]

• Complementary: Carb-veg. (late collapse), Phos. (respiratory burning), Thuja (sycotic overlay), Sil. (suppuration), China (post-loss debility), Nat-m. (allergic/catarrhal layer), Sec. (ischaemic states). [Kent], [Clarke], [Boger]
• Follows well: Acon. (storm of fear → lingering anxiety/restlessness), Ipec./Nux-v. in gastric cases shifting to burning + sips + fear; Rhus-t. in septic fevers turning to prostration and burning. [Farrington], [Nash]
• Precedes well: Carb-veg. when air hunger dominates; Phos. for residual chest burning craving cold drinks; China for fluid-loss debility. [Clarke]
• Antidotes: Camph. (drug effects), Nux-v. (over-stimulation), Ipec. (vomiting). [Hahnemann], [Clarke]
• Arsenicum antidoted by: China (periodic fevers), Ferr., Graph. for cutaneous drug effects. [Clarke]
• Inimical/Caution: Rapid alternation with Phos. can confuse thermal desires; let the case declare. [Kent]

• Food poisoning / “stomach flu” with burning epigastrium, vomiting after every sip, anguish and chilliness: Ars. 200C, water dosing; switch to Verat. if profuse purging with desire to be covered dominates. [Nash], [Farrington]
• Asthma at 1–2 a.m.: must sit up, fear of death, sips hot water, chilly—Ars. first; add steam/heat to chest. [Boger], [Clarke]
• Eczema/psoriasis burning, excoriating: Ars. intercurrent; topical bland emollients; avoid suppressive steroids if possible. [Hering], [Clarke]
• Cancer cachexia with burning, fetor, night anguish: Ars. palliative—small frequent doses; consider Carb-veg. for terminal air-hunger. [Hughes], [Farrington]
• Nephritic oedema with anxiety, thirst in sips: Ars. alongside nephrology care; watch albuminuria and BP. [Clarke]
• Mini-pearls:

• • Burning pains better heat is more decisive for Ars. than for almost any other remedy. [Hering]
  • Thirst: little and often—do not mistake for thirstlessness. [Allen]
  • Restless despite weakness—he moves because of anguish, not because motion relieves pain (contrast Rhus-t.). [Kent]

Mind

• Anxiety, fear of death, after midnight; cannot remain in one place—must move from bed to bed. Diagnostic keynote. [Kent], [Hering]
• Desires company; fear of being alone; fastidious about order and cleanliness. [Kent], [Tyler]
• Restlessness with prostration; despair of recovery. [Allen]
• Suspicious, miserly, anxious about health and money. [Clarke]

Head / Eyes / Nose

• Headache burning, better heat; cold sweat on forehead with anxiety. [Allen]
• Blepharitis with burning, acrid tears that excoriate lids. [Hering]
• Coryza acrid, excoriating; upper lip raw; sneezing in cold air. [Clarke]
• Hay fever with burning in nose/eyes; worse cold wind; better warmth. [Allen]

Stomach / Abdomen / Rectum

• Gastritis: burning pain, vomiting after drinking, thirst for small sips. [Hering]
• Diarrhoea after midnight; stools watery, offensive, burning anus. [Nash]
• Food poisoning from tainted fish/meat/ice-cream. [Clarke]
• Peritonitis with burning, great anxiety, prostration. [Boger]

Chest / Respiration / Heart

• Asthma about 1–2 a.m.; must sit up; fear of death; worse lying. [Boger]
• Burning in chest better heat; dyspnoea from slightest exertion. [Clarke]
• Palpitation with small, rapid pulse; angor animi. [Allen]

Urinary / Skin

• Albuminuria with oedema and anxiety; scant, hot urine. [Clarke]
• Ulcers with black bases, fetid; burning pains better hot applications. [Hering]
• Eczema/psoriasis burning, excoriating; worse cold; better warmth. [Allen]

Generalities

• Burning pains better heat. [Hering]
• Thirst for frequent small quantities; worse after midnight (1–2 a.m.). [Boger]
• Great prostration out of proportion to disease; fetid discharges. [Allen]
• Chilly, wants to be warmly covered; cold aggravates. [Clarke]

Hahnemann — Materia Medica Pura & Chronic Diseases (1821–1830): primary proving; burning pains > heat; thirst in sips; midnight aggravation.
Hering, C. — The Guiding Symptoms of our Materia Medica (1879–1891): gastro-enteric, respiratory, skin, ulcerative and cachectic confirmations.
Allen, T. F. — Encyclopaedia of Pure Materia Medica (1874–1879): toxicology and proving details; modalities; periodicity.
Hughes, R. — A Manual of Pharmacodynamics/Pharmacography (1867–1868): pharmacologic rationale—epithelial/vascular toxicity, cachexia.
Clarke, J. H. — A Dictionary of Practical Materia Medica (1900): clinical keynotes—food poisoning, asthma after midnight, fetor, restlessness.
Kent, J. T. — Lectures on Homoeopathic Materia Medica (1905): mental essence—fear, fastidiousness, dependence; thermal and time modalities.
Boger, C. M. — Boenninghausen’s Characteristics & Repertory (1905); Synoptic Key (1915): generalities—periodicity, after-midnight aggravation, burning > heat.
Boericke, W. — Pocket Manual of Homoeopathic Materia Medica (1901): bedside keynotes—thirst in sips, prostration, ulcerations, skin.
Farrington, E. A. — Clinical Materia Medica (1887): comparisons (Verat., Ipec., Phos., Carb-veg.); fever and gastric states.
Nash, E. B. — Leaders in Homoeopathic Therapeutics (1899): cholera/diarrhoea pearls; “rapid sinking with restlessness.”
Tyler, M. L. — Homoeopathic Drug Pictures (1932): anxious, tidy Arsenic; night fear; small sips; heat-seeking.
Phatak, S. R. — Materia Medica of Homoeopathic Medicines (1977): distilled essentials—burning better heat, midnight, prostration, fetor.
Dunham, C. — Lectures on Materia Medica (1879): periodicity, autonomic tone, collapse physiology.