Definition. Inflammatory or other conditions of the skin, due to the ingestion or absorption of medicinal substances.
Symptoms. Drugs may produce, under favoring conditions, nearly all the primary lesions which occur in skin diseases. This fact alone confirms the analogous relation existing between the pathological features of disease and the adaptability of drugs to the successful treatment of the same. While the effects of drugs upon the skin are not constant or the same in different individuals or the same in the same person at different time, this is also true as regards the so-called causes of natural diseases. Occasionally the drug action on the skin is nearly constant and specific as also may be the action of a specific cause of disease. Subjective sensations, such as itching, burning or tingling may precede, attend or follow the outbreak of the eruption. Systemic symptoms may be absent or fever, headache and malaise may appear. If long continued, some drugs lead to grave constitutional symptoms or even death. Drug eruptions may appear rapidly such as the congestive and exudative forms or more slowly, such as the eruptions from iodin and bromin salts. Erythemas are more often produced than any other lesions. Next in order are vesicles, papules, wheals, blebs, pustules, and tubercles while pigmentation, gangrene, purpura and desquamation are rarer effects. Some drugs may produce all varieties of lesions while others give rise to only one or two. It is most important that the general practitioner should be familiar with drug effects on the skin, because of their frequent resemblance to eruptive fevers and for other differential purposes. The following list does not include all the drugs which may cause skin eruptions nor does it mention the more subtle drug effects, but only designates the relative frequency of skin manifestations and mentions the common type of lesions or lesions which may be produced.
Aconite. Rare; erythema, edema, vesicles, pustules and bullae.
Acetanilid. Not common; erythema, erythematous papules and cyanosis.
Ailanthus. Rare; punctate erythema, especially on the face.
Amygdala amara (bitter almond). Rare; erythema, wheals.
Anacardium. Rare; papules, wheals, vesicles.
Antimonium crudum and tartaricum. Rare; vesicles, pustules, wheals.
Antipyrin and others of its class, manufactured from the petroleum products by the action of glacial acetic acid. Common; usually morbilliform, occasionally erythematous macules and less often papules, wheals, blebs, occasionally erythematous macules and less often papules, wheals, blebs, pustules, purpuric, spots, desquamation and pigmentation. Often accompanied with excessive sweating.
Antitoxins. Common; tuberculin rash may be scarlatiniform, morbilliform or in irregular patches. Diphtheria antitoxin causes erythematous, scarlatiniform, morbilliform, purpuric or urticarial lesions. Tetanus antitoxin has caused wheals.
Apium virus. Common; generalized eruption of wheals, erythema and edema.
Arsenic and preparations containing arsenic in some form. Common; nearly every variety of skin lesion, erythema, papules, vesicles, wheals, pustules, purpuric and psoriatic spots, pigmentation, keratosis, gangrene and ulcers.
Arum. Rare; scarlatiniform, desquamation.
Aurum metallicum and the salts of gold. Rare; pustules, wheals, nodules; the last like erythema induratum or syphilitic formations.
Belladonna-Atropin. Common; scarlatiniform erythema, vesicles, pustules, gangrene.
Benzoic acid and sodium benzoate. Rare; erythema, papules, wheals.
Boric acid and sodium borate. Rare; morbilliform erythema, papules, vesicles, pustules, scales.
Bromin compounds. Common; acneiform papulopustules, affecting the parts abundantly supplied with sebaceous glands, such as the face, back and shoulders; vesicles like varicella; pustules and furuncular or carbuncular formations; rarely; erythematous, urticarial, nodular, bullous, papillary or fungoid lesions; Occurring in children the lesions may be condylomaform.
Bryonia. Rare; erythema, papules, vesicles.
Calcarea carbonica. Rare; wheals sometimes linear, wart-like lesions.
Calcium sulphid. Common; erythema, vesicles, wheals, pustules, furuncles.
Cantharides. Rare; erythema, papules.
Capsicum. Rare; erythema; papulovesicles.
Carbolic acid. Rare; vesicles, pustules, erythema.
Chloral. Common; scarlatiniform or morbilliform erythema. More rarely, vesicles, papules, wheals or furuncular, carbuncular and purpuric lesions.
Chloralamid. Very rare; punctate erythema, vesicles, desquamation.
Chloroform. Common; erythema. Occasionally purpuric spots.
Chrysarobin. Common; coppery-red erythema, like erysipelas. Marked desquamation.
Cicuta virosa. Rare; erythema, large papules, tubercles.
Cinchona-Quinin. Common; scarlatiniform erythema, desquamation, exfoliation; itching and pricking sensations with fever. Less commonly wheals, vesicles, blebs and purpuric spots.
Cod liver oil. Rare; acneiform, vesicles.
Conium. Rare; papules, pustules, erysipelatous erythema.
Condurango. Rare; furuncular, acneiform lesions.
Copaiba and cubebs. Common; most eruptions observed from the combined use of the these drugs are due to copaiba. Scarlatiniform and morbilliform erythema, wheals, vesicles, bullae.
Digitalis. Rare; erythema, vesicles, bullae and wheals.
Dulcamara. Rare; erythema, wheals, scales.
Ergot. Rare; vesicles, pustules or furuncular, gangrenous, purpuric eruptions.
Euphorbium and other resins. Infrequent; erythema, edema, vesicles, with pain and fever; occasionally pustules, ulcers and gangrene.
Graphites. Occasional; erythema, papules, vesicles, dryness, induration, fissures. Itching and exudation.
Guaiacum. Rare; miliary erythema.
Gurjun oil. Rare; erythema and erythematous papules.
Hydrastis. Rare; erythema with severe burning.
Hyoscyamus. Occasional; edema, erythema, wheals and exceptionally, pustular and purpuric lesions.
Iodin and its compounds. Common; papules, and papulopustules (so-called iodid acne) generally on the face, neck and shoulders. The lesions may become confluent and give rise to papillomatous, condylomaform, carbuncular or crusted lesions, and occasionally a multiform or polymorphous eruption.
Iodoform. Uncommon; erythema, papules, vesicles, bullae.
Ipecac. Very rare; fiery red erythema with elevated borders; occasional wheals and vesicles.
Iris versicolor. Rare; vesicles, pustules, crusts, with neuralgic pain.
Jaborandi-Pilocarpin. Rare; erythema, miliary papules, vesicles and wheals.
Ledum. Rare; erythema, papules, vesicles, pustules.
Lycopodium. Very rare; erythema, pustules, vesicles, with itching, burning and bleeding.
Mercury and its salts. Common; erythema, papules, pustules, vesicles, bullae or purpuric, furuncular and ulcerated lesions.
Mezereum. Rare; vesicles, pustules, abundant exudation, yellowish crusts.
Nitric acid. Rare; erythema, vesicles, pustules.
Nux vomica-Strychnia. Rare; scarlatiniform erythema, vesicles, acneiform papules and pustules with pruritus.
Oil of sandalwood. Rare; simple erythema, petechial purpura.
Olium morrhuae. Rare; erythematous vesicles or acneiform papules.
Olium ricini (Castor oil). Rare; pruritic erythema.
Opium-Morphin. Common; all forms of erythema, the exudative being the most common. Wheals, vesicles, pustules, edema with itching.
Phenacetin. Rare; erythema.
Phosphorus and phosphoric acid. Rare; grouped vesicles, wheals, bullae and hemorrhages.
Piper methysticum (fermented juice of kava kava). Common; erythematosquamous, exfoliation and desquamation.
Plumbum and its salts. Rare; erythema, vesicles, pustules and purpuric lesions.
Pulsatilla. Rare; rubeoloid and urticarial eruptions.
Potassium chlorate. Rare; erythema, papules, cyanosis.
Ranunculus bulbosus. Rare; grouped vesicles with neuralgic pain.
Rhubarb. Rare; scarlatiniform; desquamative erythema.
Salicylic acid-Salicylates. Rare; erythema, wheals or rarely vesicles, bullae, purpura and gangrene.
Salol. Rare; wheals.
Santonin-Sodium santonate. Rare; wheals, with desquamation and edema, vesicles.
Sarsaparilla. Uncommon: erythema, vesicles; rarely papillary or wart-like elevations.
Silver nitrate. Rare; grayish-black pigmentation. Rarely erythematous papules.
Staphisagria. Rare; miliary papules and vesicles.
Stramonium. Rare; scarlatiniform erythema; petechial, vesicular or pustular lesions.
Sulphonal. Occasional; desquamative erythema with intense itching.
Tanacetum (Oil of Tansy). Very rare; varioliform eruption.
Tannin. Rare; morbilliform erythema, wheals.
Thallium acetate. Occasional; alopecia, more or less complete.
Thuja. Rare; papillary or wart-like excrescences which bleed easily.
turpentine-Terebene. Occasional; scarlatiniform or morbilliform erythema. Terebene: papules with pruritus.
Valerian. Very rare; urticarial papules.
Veratrum viride. Rare; erythema, pustules.
Veronal. Rare; scarlatiniform or morbilliform erythema.
Viburnum prunifolium. Rare; scarlatiniform, desquamative.
Diagnosis. Having any doubt as to the nature of an eruption, it is well to inquire what drugs or medicines have been used within the last few days or weeks. Some few remedies, if given in full doses or for some time, may be detected in the secretions or exhalations, such as turpentine and other essential oils. In general, the absence of prodromic and constitutional symptoms, lack of uniformity or order of sequence will aid in the diagnosis. For example, the scarlatiniform eruptions suddenly appear without high temperature and rapidly subside when the drug is stopped. Morbilliform eruptions have no prodromic coryza, continued fever with the eruption, or other symptoms of measles. The bromin and iodin eruptions might be mistaken for acne, variola or syphilis but the location of acne, age of occurrence, associated comedones and its chronic character should settle the identity of that disease. Variola presents fever and constitutional symptoms, together with the typical course which should distinguish it from the umbilicated papules and vesicles of the iodin eruption. Syphilis gives a history of other lesions or presents other symptoms of its existence, hardly to be mistaken.
Treatment. With the great majority if case, the discontinuance of the drug or medicine is suficient. Occasionally an antidotal drug in small doses will hasten recovery. Externally, protective measures are required when open lesions exist to prevent possible infection or soothing application to relieve irritations or subjective sensations. Drug antidotes can be found in most works on materia medica and often will assist in relieving any discomfort from which the patient may be suffering.