The essence of Fagopyrum is venous heat with itching margins. The organism is flushed and full under warmth; the skin—especially at the borders where skin turns mucosa (nostrils, anus, vulva, scrotal root)—becomes a field of crawling, pricking, and then burning if rubbed. The moment of undressing is diagnostic: as the warm skin meets room air, a storm of pruritus breaks out; covers on, it blazes; window open, it quiets. This thermal law (worse warmth/bed/undressing; better cool air/uncovering/cold ablutions) threads the whole case and reappears in the head (congestive pressure, desire to uncover), in the heart (palpitation after meals in warm rooms, relieved by a turn in the air), in the chest (oppression > open air), and in the rectum (hæmorrhoidal itching and burning, better cool washing). Pathophysiologically the picture matches a rutin-bearing polygonaceous herb: a capillary–venous remedy with reflexes in the skin. Toxicology’s “fagopyrism”—photosensitive pruritus and erythema—explains the urticarial flashes and sun-tingling that attend the remedy’s constitution [Hughes], [Clarke].
The clinical art is to separate Fagopyrum from its neighbours: Aesculus is drier, more sacral and constrained, with hard stools; Aloe has sudden, urgent, mucous stools and a lax sphincter; Ratanhia burns like knives after stool; Hamamelis bleeds and bruises; Sulphur is the archetypal heat-itch with foulness and early-morning exacerbations. Fagopyrum sits between and before them when itch prevails over pain, heat over foulness, and air and cold ablution are the direct antidotes. In the skin field it is not corrosive like Kreosotum, nor destructive and “burning-better-cold” like Euphorbium; it is a prick-and-flush remedy—the urticant storm of the venules—ending when the room cools.
Thermally the subject is warm-worse, craving air; constitutionally more restless than depressed; miasmatically Sycotic–Psoric with venous dilatation and mucous irritation. Pace is evening-centred: hot supper → flush, pruritus, palpitation; window open → relief. Practical counsel mirrors the modalities: cool the room at dusk; avoid hot baths and late spiced meals; keep clothing loose; wash the itchy margins with cool water; walk gently in the open air after meals. In prescribing, the decision often turns on the undressing test: if disrobing at night is the moment of worst itching—and if hæmorrhoidal margins behave like the rest of the skin—Fagopyrum is faithful.
Potency choice: low to mid (3x–6x/6C) for hæmorrhoidal and daily pruritic states with frequent repetition; 30C–200C when the keynote thermal law and undressing-itch are crystalline; LM/Q for chronic venous/skin cycles prone to relapse [Boericke], [Nash], [Vithoulkas]. Dose to sensation: repeat while heat-itch returns; space as the need for cold lessens. Sequencing often runs Nux vom. (dietetic excess, sedentary) → Fagopyr. (heat-itch and venous head) → Aesculus/Hamamelis (residual sacral fullness or bleeding). Clinical pearl: when a “piles” case says, “The worst is undressing and getting into bed; I must sponge with cold water and open the window,” give Fagopyrum first; the rest arrange themselves in its wake.
