Cutaneous drug reactions: pathogenesis and clinical classification

Spectrum of anti tubercular therapy induced cutaneous adverse drug reactions and its management through rechallenge: A prospective study at a Tertiary Care Centre

INTRODUCTION

The use of multi-drug regimens including 1st and 2nd line anti tubercular drugs in management of tuberculosis (TB) has been associated with undesirable adverse drug reactions including cutaneous one. Re-challenge remains the only option to restart the safe therapy and combat the tuberculous infection simultaneously.

MATERIALS AND METHODOLOGY

This cross-sectional study was conducted via prospective review of outpatients as well as indoor patients who presented with cutaneous adverse drug reactions to ATT between March 2020 and March 2021. Data were analysed regarding demographic profile, site of TB, ATT regimen, pattern of cutaneous lesions, offending drugs, past history of drug allergy, and reinstitution of ATT after re-challenge.

RESULTS

Out of total 56 registered tubercular patients presented with cutaneous adverse drug reaction 30 were females (53.57%). The most common site of TB was pulmonary followed by cervical lymph node TB. The three most common adverse drug reaction detected were maculopapular rash 32 (57.1%) followed by lichenoid drug eruptions in 6 (10.7%) and urticaria in 2 (3.6%). Ethambutol was found to be common offending drug followed by other first line anti-tubercular drugs. 5 patients developed multiple drug hypersensitivity on re-challenging and have to introduce steroids along with ATT.

CONCLUSION

Adverse cutaneous drug reactions to ATT is like a double-edged sword as stopping ATT and starting treatment with systemic steroids can further flare up the infection with increased risk of disseminated and multidrug resistant tuberculosis. Re-challenge was found out to be safest way in identifying culprit drug and hence to restart a safer alternate ATT regimen for better management.

Morbilliform Eruption After Administration of Second Dose of Oxford/AstraZeneca Vaccine

Morbilliform eruption typically implies a maculopapular rash of acute onset. Drugs are the predominant cause of this cutaneous reaction in adults, followed by infectious exanthems and some rheumatological diseases. In this article, we report on the clinical and histopathological features of generalized pruritic morbilliform eruption in a 28-year-old female following her second dose of Oxford/AstraZeneca COVID-19 vaccine. The reaction started 12 hours after receiving the vaccine with no other identifiable cause.

The patient had no improvement with IV antihistamine received in the emergency department. Afterward, she showed marked improvement after receiving a short course of oral corticosteroids along with topical corticosteroid and oral antihistamine. To the best of our knowledge, we hypothesize that the basic immunological mechanism is the cause behind COVID-19-vaccine-related morbilliform eruption. Therefore, physicians should be aware of the possible adverse reactions associated with COVID-19 vaccines, such as morbilliform eruptions and other cutaneous manifestations.

Radiodermatitis as a consequence of radiation recall induced by acyclovir: case report

Background

Radiation recall dermatitis (RRD) is an inflammatory reaction in an area of the skin previously irradiated for cancer treatment. The reaction usually occurs following the administration of a cytotoxic drug. Manifestations range from mild to severe, resulting in tissue necrosis. It is treated with removal of the probable causative agent, daily dressings and surgical debridement of the necrotic area.

Case presentation

A 54-year-old woman had a previous diagnosis of intraductal carcinoma in situ, and had been submitted to lumpectomy and adjuvant radiotherapy and hormonal therapy. One year after surgery, sores suggestive of herpes zoster infection developed, and treatment with acyclovir was started. At the same time, there was the onset of pain and fever. In the skin area previously irradiated, there was breast hardening, skin infiltration and serosanguinolent discharge. An incisional biopsy was performed to rule out radioinduced sarcoma. The patient was treated with surgical debridement.

Conclusions

This case report describes acyclovir as a possible trigger of RRD, a rare condition that could have been mistaken for an eruption with other causes. In this case, the dermatitis reaction was confined to the previously irradiated area of the skin, which suggested radiation recall. A better understanding of the condition’s mechanism and about the possible joint effects of drugs and radiotherapy on the skin is necessary.

Radiation Recall in a Patient with Intrahepatic Cholangiocarcinoma: Case Report and a Literature Review

Radiation recall dermatitis (RRD) is a rare and poorly understood phenomenon, constituting an inflammatory skin reaction to a previously irradiated area of skin following the administration of certain agents, usually chemotherapy. Our patient developed RRD 66 years after receiving radiation therapy; to the best of our knowledge, this is the longest reported period in the literature. The mainstay of therapy is to withhold the agent that elicited the adverse reaction, followed by symptomatic management. Subjecting patients to further chemotherapy can provoke another episode of RRD. Therefore, clinical judgment in this regard is usually recommended.

Oral Adverse Drug Reactions to Cardiovascular Drugs

A great many cardiovascular drugs (CVDs) have the potential to induce adverse reactions in the mouth. The prevalence of such reactions is not known, however, since many are asymptomatic and therefore are believed to go unreported. As more drugs are marketed and the population includes an increasing number of elderly, the number of drug prescriptions is also expected to increase. Accordingly, it can be predicted that the occurrence of adverse drug reactions (ADRs), including the oral ones (ODRs), will continue to increase. ODRs affect the oral mucous membrane, saliva production, and taste. The pathogenesis of these reactions, especially the mucosal ones, is largely unknown and appears to involve complex interactions among the drug in question, other medications, the patient’s underlying disease, genetics, and life-style factors. Along this line, there is a growing interest in the association between pharmacogenetic polymorphism and ADRs. Research focusing on polymorphism of the cytochrome P450 system (CYPs) has become increasingly important and has highlighted the intra- and inter-individual responses to drug exposure. This system has recently been suggested to be an underlying candidate regarding the pathogenesis of ADRs in the oral mucous membrane. This review focuses on those CVDs reported to induce ODRs. In addition, it will provide data on specific drugs or drug classes, and outline and discuss recent research on possible mechanisms linking ADRs to drug metabolism patterns. Abbreviations used will be as follows: ACEI, ACE inhibitor; ADR, adverse drug reaction; ANA, antinuclear antigen; ARB, angiotensin II receptor blocker; BAB, beta-adrenergic blocker; CCB, calcium-channel blocker; CDR, cutaneous drug reaction; CVD, cardiovascular drug; CYP, cytochrome P450 enzyme; EM, erythema multiforme; FDE, fixed drug eruption; I, inhibitor of CYP isoform activity; HMG-CoA, hydroxymethyl-glutaryl coenzyme A; NAT, N-acetyltransferase; ODR, oral drug reaction; RDM, reactive drug metabolite; S, substrate for CYP isoform; SJS, Stevens-Johnson syndrome; SLE, systemic lupus erythematosus; and TEN, toxic epidermal necrolysis.

Dermatologic Problems in the Intensive Care Unit: Part IV

In this final section of our review, we discuss a variety of skin disorders often acquired during hospitalization in the intensive care unit. Environmental, nutritional, immunologic, and pharmacologic factors, among others, place patients at risk for drug eruptions, including leukocytoclastic vasculitis and anticoagulant-induced necrosis; moniliasis; acquired zinc deficiency; recurrent herpes simplex labialis; seborrheic dermatitis; contact dermatitis; and pressure sores.

Inpatient Consultative Dermatology

Dermatology consultation can improve diagnostic accuracy in the hospitalized patient with cutaneous disease. Dermatology consultation can streamline and improve treatment plans, and potentially lead to cost savings. Dermatology consultants can be a valuable resource for education for trainees, patients, and families. Inpatient consultative dermatology spans a breadth of conditions, including inflammatory dermatoses,infectious processes, adverse medication reactions, and neoplastic disorders, many of which can be diagnosed based on dermatologic examination alone, but when necessary, bedside skin biopsies can contribute important diagnostic information.

Case report of cold-weather-induced radiation recall dermatitis after chemoradiotherapy with cisplatin

BACKGROUND

The radiation recall reaction (RRR) is an inflammatory reaction that occurs in previously irradiated areas. The phenomenon is probably due to an idiosyncratic hypersensitivity reaction, in which a second agent can recall the inflammatory reaction.

CASE REPORT

This case report documents a cold-weather-induced radiation recall dermatitis (RRD). We observed a severe RRD in a patient after chemoradiotherapy treatment with cisplatin for a nasopharyngeal carcinoma, precipitated by cold temperatures, which developed 9 days after completion of therapy. In the medical literature, RRD following extreme cold temperatures seems to be a peculiar event.

CONCLUSION

Until further information on the interaction is available, future studies on combined chemotherapy with cisplatin should be carefully monitored and any side effects clearly documented. This case suggests that environmental conditions may play a contributing role in the development of RRD. This case also implies that neither fraction size nor total radiation dose is a determining factor in the development of the dermatologic reaction.

Hydroxychloroquine-associated hyperpigmentation mimicking elder abuse

Background

Hydroxychloroquine may result in cutaneous dyschromia. Older individuals who are the victims of elder abuse can present with bruising and resolving ecchymoses.

Purpose

The features of hydroxychloroquine-associated hyperpigmentation are described, the mucosal and skin manifestations of elder abuse are reviewed, and the mucocutaneous mimickers of elder abuse are summarized.

Case Report

An elderly woman being treated with hydroxychloroquine for systemic lupus erythematosus developed drug-associated black and blue pigmentation of her skin. The dyschromia was misinterpreted by her clinician as elder abuse and Adult Protective Services was notified. The family was eventually cleared of suspected elder abuse. A skin biopsy of the patient’s dyschromia confirmed the diagnosis of hydroxychloroquine-associated hyperpigmentation.

Conclusion

Hyperpigmentation of skin, mucosa, and nails can be observed in patients treated with antimalarials, including hydroxychloroquine. Elder abuse is a significant and underreported problem in seniors. Cutaneous findings can aid in the discovery of physical abuse, sexual abuse, and self-neglect in elderly individuals. However, medication-associated effects, systemic conditions, and accidental external injuries can mimic elder abuse. Therefore, a complete medical history and appropriate laboratory evaluation, including skin biopsy, should be conducted when the diagnosis of elder abuse is suspected.

Adverse Cutaneous Reactions and Drugs: A Focus on Antimicrobials

Rashes are a common adverse event observed during antimicrobial therapy. Many rashes are mild to moderate in intensity, however some reactions can be the prelude to much more severe outcomes such as Stevens-Johnson Syndrome (SJS) or Toxic Epidermal Necolysis. Several risk or influencing factors are known such as female gender, age and concomitant viral infections, and these may apply to more than one drug class. The incidence of rashes and other cutaneous reactions vary, however rates of >3% are reported with the beta-lactams while serious reactions such as SJS are observed with trimethoprim-sulphamethoxazole. Newer fluoroquinolone agents are devoid of the moiety which caused phototoxic reactions, while rates of rash vary from < 1%-3% or higher if longer courses of therapy are given. Serious systemic events have not been reported with these agents unlike other older, well-accepted antimicrobials. Rashes, while occasionally itchy and sometimes transiently unsightly, have less of an impact on a patient's daily activities than diarrhea, nausea or other more profound adverse events. However, it is essential that any rash be carefully monitored for possible, but rare, serious systemic events ensuing.

Cutaneous drug eruptions: a 5-year experience

BACKGROUND

The diversity of cutaneous drug eruptions encompasses many clinicopathologic entities.

METHODS

Cases with a pathologic diagnosis of drug eruption from 2000 to 2005 were retrieved from our institution. The histologic slides were reviewed, the patterns of inflammatory changes were recorded, and a chart review was performed.

RESULTS

The majority of the cases (94%) were "morbilliform"-type rashes. Eighty-two percent of cases exhibited an inflammatory infiltrate confined to the superficial dermis. Eighty percent exhibited a perivascular and interstitial pattern of dermal infiltrate. The infiltrate was composed of lymphocytes and eosinophils in approximately 29% of cases, lymphocytes and neutrophils in approximately 10% of cases, and lymphocytes, eosinophils, and neutrophils in approximately 21% of cases. Eosinophils were present in only 50% of cases. Approximately half (53%) of the cases exhibited epidermal-dermal interface changes.

LIMITATIONS

The cases were limited to those with a pathologic diagnosis of cutaneous drug reaction, thereby excluding any cases with drug-induced disease not specifically diagnosed (histologically) as such.

CONCLUSIONS

While the histologic features of most drug eruptions are not entirely specific, the finding of superficial infiltrates composed variably of lymphocytes, neutrophils, and eosinophils, either with or without interface changes, should suggest the possibility of a morbilliform drug eruption. Clinical correlation is very helpful to confirm the diagnosis. To our knowledge, this study is the most extensive documenting the histologic findings in morbilliform drug eruptions.

Cutaneous Reactions to Antibacterial Agents

Antibacterial agents may cause a variety of untoward reactions. Some range from transient, mild erythema to toxic epidermal necrolysis, often resulting in disability and death. Both in vivo and in vitro tests are becoming useful for the diagnosis of the causative agent in drug eruptions. The drug hypersensitivity syndrome may be associated with thyroid abnormalities often occurring months after the drug has been withdrawn. Symmetrical small joint polyarthritis, fever, and malaise may be the presenting findings in a patient with drug-induced lupus erythematosus. Exanthematous drug eruptions without high fever, mucosal involvement, or joint symptoms often resolve without discontinuation of the drug. The differential diagnosis of Stevens-Johnson syndrome and toxic epidermal necrolysis depends on the percentage of epidermal detachment.

UV-light induced radiation recall dermatitis after a chemoradiotherapy organ preservation protocol

This case report documents a UV-light-induced recall phenomenon and reviews the medical literature. In this patient, we observed a severe recall phenomenon precipitated by an extensive sunlight exposure after a chemoradiotherapy organ preservation protocol. Radiation recall phenomenon is a rare but well-described phenomenon, without clear radiation or drug-specific characteristics. In the medical literature, radiation recall following UV-sunlight exposure seems to be an exceptional event. The etiology remains unknown but could involve local hypersensitivity through a non-immune activation of inflammatory pathways. Due to the increasing number of patients with head and neck malignancies managed with induction chemotherapy and/or chemoradiation organ preservation protocols, the otorhinolaryngologist--head and neck surgeons as well as the radiation therapist should become aware and familiar with this phenomenon.

Adverse cutaneous drug eruptions and HIV: a clinician's global perspective

Adverse drug reactions (ADRs) are common and mostly avoidable. Some ADRs cannot as yet be predicted, but at-risk populations/patients and high-risk drugs are identifiable. HIV-infected patients are at risk of developing cutaneous ADRs, especially Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug hypersensitivity syndrome. Multiple factors of causation variably present in patients with HIV infection best explain the pathogenesis of these cutaneous ADRs. When no effective alternate therapy is available, drug rechallenge in HIV-infected patients can be attempted with little morbidity or mortality if done according to rationalized protocols.

A Case of Skin Hypopigmentation Secondary to a Corticosteroid Injection

A 47-year-old African-American male presented complaining of Achilles tendon pain. The patient was treated for three weeks with a nonsteroidal anti-inflammatory agent with minimal pain relief. The tendon was subsequently injected with triamcinolone acetonide and five months later, the patient presented with an area of hypopigmentation around the injection site. The patient was diagnosed with hypopigmentation secondary to the steroid injection.

Immune response to xenobiotics in the skin: from contact sensitivity to drug allergy

Skin is the most frequent target of adverse drug reactions. These cutaneous drug reactions (CDRs) show varied clinical manifestations ranging from mildly discomforting rashes to life-threatening Stevens-Johnson syndrome or toxic epidermal necrolysis. Most CDRs appear to be immune mediated, although the mechanism by which they are initiated remains unclear. In this review, current knowledge of the mechanisms by which xenobiotics provoke immune responses in the skin after epicutaneous administration and how similar reactions may occur after systemic routes are summarised. This review also discusses a variety of genetic or environmental factors that may determine the susceptibility of individuals towards immune responses in skin following drug exposure.

Gemcitabine-related radiation recall in a patient with pancreatic cancer

Radiation recall refers to inflammatory reactions triggered by chemotherapeutic agents and develops cutaneously in the previously irradiated areas. Such agents include anthracyclines, taxanes and capecitabine. Radiation recall related to gemcitabine has been reported in lung and breast cancer. Similar phenomenon associated with gemcitabine, the only FDA-approved drug for pancreatic cancer, is rarely reported. We report a patient with inoperable pancreatic cancer who developed gastrointestinal bleeding secondary to radiation-recall related to gemcitabine and review literature. A 57-year-old white male with unresectable pancreatic cancer received capecitabine in combination with radiation therapy followed by capecitabine alone given over approximately a 3-month time period. Computed tomography re-evaluation demonstrated a new liver lesion. The patient was then treated with gemcitabine and irinotecan. On day 15 of cycle 1, he reported progressive worsening of weakness and fatigue, and melena. Physical examination revealed hypotension (84/47 mmHg) and heme-positive stool on rectal examination. He denied aspirin or non-steroidal anti-inflammatory drug use. Chemotherapy was held. Hematocrit was 20% (previously 33%). He was transfused with 3 units of packed red blood cells. An esophago-gastro-duodenal examination was performed which showed antritis and duodenitis consistent with radiation therapy. A single site of oozing was injected with epinephrine. The diffuse gastritis was aggressively treated with proton pump inhibitors. The patient's hematocrit eventually stabilized and was 30% at discharge. Gemcitabine was not resumed. Radiation recall from gemcitabine is rare, but can potentially arise in any site that has been previously irradiated. Gemcitabine should be added to the list of drugs known to cause radiation recall. Treating physicians must be aware of this potential toxicity from gemcitabine either given concomitantly or followed by radiation. We suggest discontinuing gemcitabine if radiation recall is observed. Further studies are warranted into the pathogenesis of this unique phenomenon.

Histological spectrum of cutaneous reactions to aspirin in chronic idiopathic urticaria

BACKGROUND

During a clinical trial, we obtained 16 biopsies of skin eruptions induced by aspirin in patients with chronic idiopathic urticaria (CIU). In this setting, aspirin triggers skin eruptions through a well-established non-immunological mechanism involving the inhibition of cyclooxygenase type I. This presented the rare opportunity to evaluate histological features of a series of skin eruptions induced by a drug acting through a defined mechanism in a controlled experimental setting.

OBJECTIVE

Histological analysis of 16 biopsies of skin eruptions induced by oral aspirin challenge in patients with CIU.

DESIGN

Microscopic analysis of tissue sections.

PATIENTS

16 patients with CIU.

RESULTS

Aspirin (up to 500 mg) induced a restricted range of histological responses with a classic pattern of urticarial tissue reaction occurring in the majority of (12 of 16) cases. Two biopsies showed an interstitial fibrohistiocytic (granuloma annulare-like) reaction pattern. One case showed only a sparse perivascular lymphocytic infiltrate, and paucicellular dermal mucinosis was observed in one case.

CONCLUSIONS

Polymorphism of histological patterns induced by aspirin suggests that in addition to the drug-specific mechanisms triggering drug eruptions, individual factors also play a role in determining the ultimate histological phenotype of a drug response.

Gemcitabine-related radiation recall preferentially involves internal tissue and organs

Radiation recall refers to inflammatory reactions triggered by cytotoxic agents and develops in previously irradiated areas. Most reactions develop cutaneously. The most common chemotherapeutic agents implicated are anthracyclines and taxanes. Gemcitabine, a nucleotide analog, recently was implicated in several cases. The authors performed a literature search using PubMed and the search terms "gemcitabine" and "radiation recall" to find prior cases of radiation recall attributed to gemcitabine. These cases were compared with those attributed to anthracyclines and taxanes. The literature search found 12 cases of radiation recall caused by gemcitabine. The authors also determined that their case of myositis developing in the rectus abdominus muscle of a patient with pancreatic adenocarcinoma was the manifestation of radiation recall, thereby bringing the number of patients who developed radiation recall to gemcitabine and were discussed in the current study to 13. Approximately 70% of the cases manifested as inflammation of internal organs or tissues and 30% manifested as a dermatitis or mucositis. This finding differs from other common agents, in which 63% of the radiation recall events are reported to manifest as a dermatitis. Compared with anthracyclines and taxanes, the interval from the completion of radiation therapy to the initiation of chemotherapy is less for gemcitabine (median time of 56 days for gemcitabine, compared with 218 days for the taxanes and 646 days for doxorubicin). The majority of radiation recall reactions attributed to gemcitabine are reported to affect internal tissue or organs. In contrast, other common agents for the most part trigger cutaneous inflammation. The development of internal tissue inflammation is reportedly correlated with a shorter interval from the time of completion of radiation therapy to the initiation of chemotherapy.

Progress in the understanding of the pathology and pathogenesis of cutaneous drug eruptions : implications for management

Cutaneous drug eruptions are among the most common adverse reactions to drug therapy. The etiology may reflect immunologic or nonimmunologic mechanisms, the former encompassing all of the classic Gell and Combs immune mechanisms. Cumulative and synergistic effects of drugs include those interactions of pharmacokinetic and pharmacodynamic factors reflecting the alteration by one drug of the effective serum concentration of another and the functions of drugs and their metabolites that interact to evoke cutaneous and systemic adverse reactions. Recent observations include the role of concurrent infection with lymphotropic viruses and drug effects that, through the enhancement of lymphoid blast transformation and/or lymphocyte survival and the contribution of intercurrent systemic connective tissue disease syndromes, promote enhanced lymphocyte longevity and the acquisition of progressively broadening autoantibody specificities. The latter are particularly opposite to drug-induced lupus erythematosus and to drug reactions in the setting of HIV infection. Specific common types of cutaneous drug eruptions will be discussed in this review. Successful management of cutaneous drug eruptions relies upon the prompt discontinuation of the causative medication; most drug eruptions have a good prognosis after this is accomplished. Oral or topical corticosteroids can be administered to aid in the resolution of some types of eruptions. Antihistamines or anti-inflammatory agents may also be administered for some eruptions.

Toxic epidermal necrolysis: differential diagnosis of an epidermolytic dermopathy in a hematopoietic stem cell transplant recipient

Toxic epidermal necrolysis (TEN) is an epidermolytic skin disorder associated with drug administration. It is associated with an erythematous rash with full thickness epidermal loss and characteristic histology. A 35-year-old woman underwent allogeneic hematopoietic stem cell transplantation (HSCT) for severe aplastic anemia (SAA). She developed an acute epidermolytic rash and TEN was diagnosed on the basis of skin biopsy. In the HSCT setting, TEN should be thought of as an important differential diagnosis of epidermolytic dermopathies. The most distinctive diagnostic test in the differential diagnosis of these disorders is skin biopsy

Fixed drug eruption following metronidazole therapy and the use of topical provocation testing in diagnosis

Fixed drug eruption is characterized by recurrent well-defined lesions appearing in the same location each time the drug responsible is taken. A number of agents have been implicated. Metronidazole, a nitroimidazole agent widely used for its antibacterial and antiprotozoal activity, has been reported only rarely as the causative agent. We describe a patient with FDE due to metronidazole in whom we were able to induce the clinical and histological features of FDE by topical provocation testing. In agreement with the published literature we commend the use of topical provocation testing as a possible first-line investigation in the diagnosis of FDE. This may avoid the need for subsequent oral provocation testing and therefore the prevention of possible adverse sequelae.

Management of cutaneous drug reactions

Drugs are potent chemicals that often have effects in the body beyond the desired action. These effects may range from mild and expected side effects to dramatic and life-threatening anaphylaxis. Adverse drug reactions account for between 2% and 6% of hospital admissions and may prevent administration of otherwise effective therapeutic agents. Cutaneous and mucocutaneous eruptions are the most common adverse reactions to oral or parenteral drug therapy, and the spectrum ranges from transitory exanthematous rash to the potentially fatal toxic epidermal necrolysis. Different mechanisms, including both immunologic and nonimmunologic, are responsible for cutaneous adverse drug reaction. The treatment of cutaneous drug eruptions essentially rests on accurate history, a thorough physical examination, discontinuation of the offending drug, and supportive care. The management of a cutaneous drug eruption is very much individualized, based on the clinical setting. This review aims to provide a general approach to the patient with a presumed cutaneous drug reaction.

Characterizing the phenomenon of radiation recall dermatitis

Radiation recall represents the 'recalling' of an effect similar in appearance to that of an acute radiation reaction in a previously irradiated field. The recall is triggered by the administration of certain drugs days to years after the exposure to ionizing radiation. This review focuses almost exclusively on the skin manifestations of radiation recall to assemble the largest data base upon which to discuss this rare phenomenon. No absolute radiation dose threshold is apparent, but rather an interplay between dose and time before drug exposure seems to affect both the risk and speed of onset of recall. Recall usually occurs on first exposure to a particular recall-triggering drug. The skin reaction develops within minutes to days. The time to develop the reaction may be slightly longer for oral than intravenously administered drugs reflecting their bioavailability. Most drugs associated with recall are cytotoxics, but several other drugs may elicit the phenomenon. Individuals exposed to a number of potentially recall-triggering drugs reveal the marked drug specificity characteristic of the phenomenon. Skin reactions usually settle within a few days of stopping the triggering drug. The role of steroids or anti-histamines in affecting resolution is unclear. Drug rechallenge tends to produce either only a mild recurrence or no recurrence of recall. Steroids or dose reduction may favour uneventful rechallenge. A number of aetiological hypotheses on radiation recall exist. Using the available evidence these hypotheses are critically reviewed and a novel hypothesis based on radiation affecting local cutaneous immunological responses proposed.

Drug-induced solar urticaria due to tetracycline

Solar urticaria is an uncommon disorder characterized by pruritus, erythema and whealing commencing within minutes of exposure to ultraviolet (UV) and visible light, and generally resolves in a few hours. We describe a 28-year-old woman who developed pruritus and erythema 5 min after sun exposure while on tetracycline for treatment of perioral dermatitis. Phototesting elicited urticarial reactions in the UVA, UVB and visible spectra. Repeat phototesting after cessation of tetracycline was negative. This report documents the first case of solar urticaria induced by tetracycline.

Common and unusual cases seen by an inpatient dermatology consult service

This article describes common consult requests and presents case studies from the dermatology consult service of an academic hospital.

Use and monitoring of bromides in epilepsy treatment

Bromides are no longer a mainstay of epilepsy therapy because of the significant toxicity associated with their use and the availability of safer agents. However, bromides occasionally find a niche in the treatment of patients with refractory seizures, particularly in pediatrics. When the decision to utilize this therapy is made, the clinician may be frustrated by the lack of concise, current information regarding bromides. This review provides an update on the mechanism of action, efficacy, pharmacokinetics, dose, and adverse effects of bromides.

Drug-induced severe skin reactions. Incidence, management and prevention

Severe skin adverse drug reactions can result in death, but the rate of such events is fortunately low. The incidences of Stevens-Johnson syndrome and toxic epidermal necrolysis range from 1.2 to 6 per million per year and 0.4 to 1.2 per million per year, respectively. Stevens-Johnson syndrome is fatal in about 5% and toxic epidermal necrolysis in 30% of cases. Drugs implicated in these diseases are the sulphonamides, anticonvulsants, allopurinol, pyrazolone derivatives, oxicams and chlormezanone. The principles of symptomatic treatment are the same as for burns, and patients with extensive skin detachment should be transferred to an intensive care unit or a burn centre. Hypersensitivity syndrome is characterised by mucocutaneous eruption and fever with frequent lymphadenopathy, hepatitis and eosinophilia. Drugs implicated are mainly anticonvulsants and sulphonamides. The mortality rate of such a reaction has been estimated to be about 8%. Corticosteroid therapy has been widely used in hypersensitivity syndrome, despite the lack of controlled studies. Drug-induced vasculitis and serum sickness may also be life-threatening when the kidney, liver, gastrointestinal tract or nervous system are involved. In angioedema, congestion may involve mucous membranes and therefore impair swallowing and ventilation. Drugs associated with angioedema include penicillins, radiographic contrast agents and ACE inhibitors. Severe forms of angioedema necessitate epinephrine (adrenaline) subcutaneous injection and possibly resuscitative efforts. Corticosteroids and/or antihistamines are used to block or reduce prolonged or late phase reactions. Prompt recognition and withdrawal of the suspected drug is essential in severe drug-induced skin reactions.

Topical provocation of fixed drug eruption. A study of 30 patients

Topical provocation with the causative agent was performed in 30 patients with fixed drug eruption (FDE). The epicutaneous open test method was used on inactive sites of old FDE lesions. Drugs at 10% in the vehicles petrolatum, alcohol and dimethylsulfoxide (DMSO) were used as test preparations. Positive reactions were always seen with phenazone salicylate (16 patients) and carbamazepine patients (3 patients), and in an individual case from chlormezanone. Both positive and negative reactions were seen with trimethoprim (3 and 2, respectively), doxycycline (2 and 1) and sulfadiazine (1 and 1). Control tests on unaffected skin with drug preparations and pure vehicles remained negative. The present results confirm our previous observation that topical provocation is a reliable test method in FDE caused by phenazone salicylate. The present study also shows that topical provocation may be useful in FDE caused by carbamazepine. In FDE caused by trimethoprim, doxycycline and sulfonamides, a positive, but not a negative, skin reaction is informative.

Patch testing in cutaneous reactions caused by carbamazepine

The usefulness of patch testing in the diagnosis of carbamazepine-induced allergic skin eruptions was studied in 18 patients with previous histories of skin eruptions caused by carbamazepine. The etiological role of carbamazepine was ascertained by peroral or topical provocation in 15 (out of 18) patients. The clinical reactions caused by the drug were classified as maculopapular exanthema with general symptoms (7 patients), other type of exanthema (3), exfoliative dermatitis (erythroderma) (3), fixed drug eruption (3), erythema multiforme (1) and urticaria (1). Patch testing showed positive reactions to carbamazepine in 7 patients; in addition, 2 patients had doubtful reactions. Positive patch test reactions were seen only in patients with exfoliative dermatitis (all 3 patients) and maculopapular exanthema (4 out of 7). None of the patients with fixed drug eruption, erythema multiforme or urticaria, or the control subjects, had positive patch test reactions to carbamazepine. The present study suggests that patch testing is useful in the diagnosis of carbamazepine allergy in patients with maculopapular eruptions or erythrodermas.

Cutaneous disease and drug reactions in HIV infection

BACKGROUND

Skin diseases, including adverse reactions to drugs, are thought to be more common among patients with human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS) than among other persons. These skin conditions can be disabling or disfiguring and may require discontinuation of essential drugs.

METHODS

We identified 684 HIV-infected members of a 265,000-member health maintenance organization and reviewed their medical records to determine the frequency of dermatologic diagnoses from April 1, 1988, through January 15, 1991. We compared the rates of visits per year for skin conditions by HIV-infected men, 20 to 49 years of age, with those by non-HIV-infected men. We used an automated prescription data base to quantify exposures to drugs.

RESULTS

Of the 684 HIV-infected patients, 540 (79 percent) were given one or more dermatologic diagnoses, for a total of 2281 diagnoses, including 188 cutaneous reactions to drugs. There were 43 hospitalizations for cellulitis (n = 15), cutaneous drug reactions (n = 13), or other skin problems. As compared with non-HIV-infected men, the men with AIDS had visit rates that were at least 5 times higher for 18 of the 20 most common infectious and inflammatory skin conditions and at least 15 times higher for 9 conditions. Drugs with the highest rate of cutaneous reactions (per 1000 courses) included trimethoprim-sulfamethoxazole (149), sulfadiazine (200), trimethoprim-dapsone (156), and aminopenicillins (93). The number of diagnoses of skin conditions increased according to the stage of disease: it was lowest in patients immediately before the documentation of HIV infection and highest in patients with a diagnosis of AIDS.

CONCLUSIONS

Cutaneous diseases, including drug reactions, are extremely common in patients with HIV infection, and their incidence increases as immune function deteriorates.

Minocycline-induced Sweet's syndrome

This is the second reported case of minocycline-induced Sweet's syndrome (and the first such case to appear in the American literature). The syndrome developed in a 32-year-old man 10 days after minocycline therapy for acne was begun and resolved rapidly after discontinuation of the medication and start of oral prednisone therapy.