Pattern Analysis of Drug-Induced Skin Diseases

Histopathologic and Clinical Characterization of Brentuximab Vedotin-associated Rash

Rash is one of the commonly observed adverse events with brentuximab vedotin (BV), a CD30-targeted antibody-drug conjugate used to treat cutaneous T-cell lymphoma (CTCL). However, clinical and histopathologic characterization of BV-associated rash (BVAR) is limited. Distinguishing BVAR from a patient's underlying CTCL can be challenging and can lead to treatment interruptions or even premature drug discontinuation. We performed a thorough clinical and histopathologic retrospective characterization of BVAR from a single institution. Utilizing polymerase chain reaction (PCR) and T-cell receptor high-throughput sequencing (TCR-HTS), we were able to isolate skin biopsy specimens from rash clinically suggestive of BVAR that also lacked a dominant TCR clone. A retrospective evaluation was performed of 26 biopsy specimens from 14 patients. Clinical features of BVAR included predominantly morbilliform or maculopapular morphology, delayed onset, and the trend toward moderate to severe classification, often requiring oral steroids. Most histopathologic specimens (25/26) showed spongiotic dermatitis as the primary reaction pattern. Many cases showed subtle findings to support a background interface or lichenoid eruption. Langerhans cell microabscesses were seen in one-fourth of specimens, and eosinophils were present in over one-half of the specimens. There were focal features mimicking CTCL, but these were not prominent. In 17 specimens with immunohistochemistry, the CD4:CD8 ratio in intraepidermal lymphocytes was relatively normal (1-6:1) in 65% (11/17) and 1:1 in 35% (6/17), demonstrating a trend toward increased CD8-positive cells compared with baseline CTCL. We have identified features that can help distinguish BVAR from a patient's CTCL, which can, in turn, help guide appropriate clinical management.

Clinical and Histopathologic Spectrum of Toxic Erythema of Chemotherapy: A Series of 56 Cases From a Single Institution

INTRODUCTION

Although many individual cases and small series of toxic erythema of chemotherapy (TEC) have been described, the full spectrum of findings is not well understood.

OBJECTIVE

To provide a comprehensive review of the clinical and histopathologic features of TEC with an emphasis on novel histopathologic findings.

METHODS

We searched our electronic medical record for "toxic erythema of chemotherapy" or "neutrophilic eccrine hidradenitis." Fifty-six cases meeting clinical and histopathologic criteria were identified. The electronic medical record and accompanying hematoxylin and eosin-stained slides were retrospectively reviewed.

RESULTS

The clinical findings were heterogeneous but included classic presentations such as intertriginous eruptions (34%) and acral erythema (25%). The most common histopathologic features were apoptotic keratinocytes (95%), basal vacuolar change (91%), and epithelial dysmaturation (79%). Eccrine squamous syringometaplasia was seen in over half of the cases (33/56; 59%), whereas neutrophilic eccrine hidradenitis was uncommon (16%). Interestingly, many cases showed prominent interstitial histiocytes (55%). Other novel findings included irregular orthohyperkeratosis (23%), irregular epidermal hyperplasia (14%), and acantholysis (9%).

LIMITATIONS

As a retrospective study, it is subject to information bias.

CONCLUSION

This is the largest reported series of TEC. In addition to confirming previously reported features, we identify novel histopathologic findings to add to the spectrum of TEC.

Psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors

PD-1 (programmed Death-1) immune checkpoint inhibitors have provided significant benefits to tumor patients. However, a considerable proportion of the patients develop immune-related adverse events (irAEs), of which cutaneous irAEs (cirAEs, e.g., psoriasis) occur relatively early. This review provides an overview of the current progress in psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. It not only describes the relevant influencing factors but also theoretically analyzes the immunological mechanisms that lead to the onset or exacerbation of psoriasis. Finally, the authors present guidelines for the treatment of psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. The review is intended to assist dermatologists in the early recognition and effective individualized management of such cirAE, which is helpful to continue or adjust the tumor-targeted immunotherapy on the basis of ensuring the quality of life of tumor patients.

Odynophagia as the first manifestation of toxic epidermal necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are infrequent mucocutaneous diseases, rapidly progressive and life-threatening. The clinical aspects and the management of TEN are exposed following a case.A man in his 40s presented to the emergency department with severe odynophagia, poor general condition and fever. His medical history was significant for HIV stage AIDS, and the treatment was discontinued 5 years before the present diagnosis. He was admitted for cerebral toxoplasmosis and discharged the previous 14 days with sulfadiazine. Erythematous-bullous lesions in the oral cavity, diffuse erythematous maculopapular rashes over his neck and chest, acute bilateral conjunctivitis and purulent urethritis was observed. The diagnostic suspicion was SJS/TEN due to sulfadiazine in immunosuppressed patients.This entity is infrequent but is a life-threatening dermatological emergency that requires immediate medical attention. Its diagnosis is mainly clinical, with a new drug history, prodromal symptoms and characteristic cutaneous-mucous lesions. Early diagnosis and rapid withdrawal of the drug improve the prognosis.

Psoriasiform Drug Eruption to Finasteride: Uncommon Side Effect of a Commonly Used Drug

Finasteride, a 5-α reductase inhibitor, is generally well tolerated on long-term use and cutaneous adverse events have rarely been observed with the drug. We present the case of a 25-year-old male who developed an extensive psoriasiform eruption within a week of starting finasteride 1 mg for androgenetic alopecia.

Updates and Proposed Diagnostic Approach to Psoriasiform Dermatoses

Psoriasiform dermatoses represent a wide array of skin diseases commonly encountered by clinicians and pathologists. While they may present a diagnostic challenge, thorough observation coupled with proper interpretation of subtle additional clinical or histopathologic features provide clues to the correct diagnosis. In this review, we provide updates on emerging entities and develop a systemic approach to establish the pathologic diagnosis, with emphasis on the importance of clinicopathologic correlation.

The Mixed Spongiotic and Interface Reaction Pattern: A Study of Clinical and Histopathologic Findings

BACKGROUND

Categorization of biopsy specimens into inflammatory reaction patterns is central to dermatopathologic assessment. Mixed inflammatory patterns are poorly characterized and may represent clinicopathologic challenges. The purpose of this study was to identify clinical and histopathologic findings associated with the mixed spongiotic-interface dermatitis (SID) histopathologic pattern.

METHODS

Fifty-one institutional biopsy specimens of SID were identified over a 2-year period by retrospective natural language search. Histopathologic and clinical features were identified.

RESULTS

The most common histopathologic features associated with SID were mild spongiosis (51%), focal vacuolar interface change (72%), lymphocytic exocytosis (92%), and superficial-dermal lymphocytic infiltrate (94%) with variable eosinophils (61%). Clinically, 80% of subjects presented with a symmetric morbilliform eruption. Polypharmacy (94%), immunosuppression (47%), and history of malignancy (47%) were common. The most common diagnoses were drug reaction (37%), possible drug reaction (12%), and viral exanthem (12%). Drug reaction with eosinophilia and systemic symptoms represented 25% of all confirmed cutaneous adverse drug reactions (CADR). Average time from drug initiation to symptom initiation was 20 days (SD: 22.3, range: 0-90); median disease duration was 25.5 days. Spongiotic vesicles and Langerhans cells were less common in patients with a strong clinicopathologic diagnosis of drug reaction compared to non-drug eruptions (p = 0.04).

CONCLUSIONS

The mixed SID pattern is commonly encountered in CADR but may represent a more subacute course, implying consideration for inciting medication(s) started before the typical 7- to 14-day window.

Histopathologic Features of Maculopapular Drug Eruption

Background: Cutaneous adverse drug reaction (CADR) is common in both inpatient and outpatient clinical settings and has been associated with a large variety of medications. Drug reactions represent a significant burden to the healthcare system due to increased hospital stay durations and associated costs. Moreover, some of these reactions may be life-threatening. The most common clinical manifestation of a CADR is a maculopapular drug eruption (MDE). Due to its many clinical mimics and associations with a variety of histopathologic patterns, maculopapular drug eruption is difficult to definitively diagnose from both a clinical and histopathological perspective. Summary: We reviewed the clinical and histopathologic features of 327 cases of MDE from several studies in the literature and summarized characteristic histopathologic findings and their frequencies of occurrence. We found that the most common and suggestive histopathologic features of MDE were epidermal spongiosis, lymphocytic infiltrate, and occasional necrotic keratinocytes; interface change at the DEJ; superficial perivascular and interstitial lymphocytic infiltrate with or without eosinophils and neutrophils in the mid-to-deep dermis and mild papillary dermal edema; and dilation of superficial vessels. The presence of multiple histopathologic patterns within the same tissue specimen is also suggestive of MDE. This review and analysis suggest that a biopsy may improve the diagnostic accuracy by both establishing common and uncommon features associated with MDE and reviewing features that help to exclude other causes of maculopapular eruption. Key Message: Histopathologic criteria for the diagnosis of MDE, while not entirely specific, may aid in establishing a differential that includes a drug eruption. Thus, a biopsy can be a helpful diagnostic tool when MDE is suspected by demonstrating findings suggestive of MDE or by ruling out clinical mimics. However, biopsy results cannot be used in isolation as clinical-pathologic correlation is paramount in MDE.

Drug hapten-specific T-cell activation: Current status and unanswered questions

Drug haptens are formed from the irreversible, covalent binding of drugs to nucleophilic moieties on proteins, which can warrant adverse reactions in the body including severe delayed-type, T-cell mediated, drug hypersensitivity reactions (DHRs). While three main pathways exist for the activation of T-cells in DHRs, namely the hapten model, the pharmacological interaction model and the altered peptide repertoire model, the exact antigenic determinants responsible have not yet been defined. In recent years, progress has been made using advanced mass spectrometry-based proteomic methods to identify protein carriers and characterise the structure of drug-haptenated proteins. Since genome-wide association studies discovered a link between human leukocyte antigens (HLA) and an individual's susceptibility to DHRs, much effort has been made to define the drug-associated HLA ligands driving T-cell activation, including the elution of natural HLA peptides from HLA molecules and the generation of HLA-binding peptides. In this review, we discuss our current methodology used to design and synthesise drug-modified HLA ligands to investigate their immunogenicity using T-cell models, and thus their implication in drug hypersensitivity.

Dermoscopic Aspects of Cutaneous Adverse Drug Reactions

Background

Little is known about the dermoscopic evaluation of cutaneous adverse drug reactions (CADRs).

Objectives

To evaluate the dermoscopic patterns of CADRs and identify those associated with severe cutaneous adverse reactions to drugs (SCARDs).

Patients and Methods

Patients included in this study from May 2015 to April 2016 had presented with CADRs. CADR presentation and classification were based on standard criteria. SCARDs included Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), overlap SJS/TEN, drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP). The dermoscopic features of CADRs were described and compared according to the severity of the reactions.

Results

Sixty-nine patients were included. Sixteen patients (23.2%) presented SCARDs. The main dermoscopic findings in SJS, overlap SJS/TEN and TEN were black dots or necrotic areas (100%). Erosion [respectively, 4/6 (66.7%), 3/3 (100%) and 1/1 (100%)], necrotic borders [respectively, 4/6 (66.7%), 3/3 (100%) and 1/1, (100%)] and epidermal detachment [respectively, 5/6 (83.3%); 2/3 (66.7%) and 1/1 (100%)] were also common among these reactions. Erythema and purpuric dots were the main dermoscopic findings [respectively, 5/6 (83.3%) and 4/6 (66.7%)] in DRESS. In non-severe reactions, the most prevalent structures were erythema and purpura in exanthema [respectively, 31/33 (93.9%) and 24/33 (72.7%)] and erythema and vascular structures in urticarial reactions [respectively, 6/6 (100%) and 3/6 (50%)]. Black dots or necrotic areas, epidermal detachment, necrotic borders and erosion were highly associated with SCARDs (P < 0.001).

Conclusions

Dermoscopy improves clinical recognition of SCARDs.

Histopathologic Characterization of Mogamulizumab-associated Rash

Rash is one of the most common adverse events observed with mogamulizumab, an anti-C-C chemokine receptor 4 monoclonal antibody approved for previously treated mycosis fungoides (MF) and Sezary syndrome (SS). Given the nonspecific clinical presentations of this rash, histopathologic distinction from MF/SS is critical for informing clinical management. We performed a comprehensive characterization of the histopathologic findings in mogamulizumab-associated rash (MAR) with the integration of high-throughput sequencing of T-cell receptor (TCR) genes. Fifty-two biopsy specimens from 19 patients were evaluated retrospectively. Three major histologic reaction patterns were identified: spongiotic/psoriasiform dermatitis (33/52), interface dermatitis (11/52), and granulomatous dermatitis (8/52). Almost half of the specimens (21/52) showed at least 2 of these reaction patterns concurrently. Dermal eosinophils were not a consistent feature, being present in only half (27/52) of specimens and prominent in only 3. Features mimicking MF/SS, including lymphocyte exocytosis, lamellar fibroplasia, and adnexal involvement, were commonly seen but tended to be focal and mild. In 38/43 specimens with available immunohistochemistry, intraepidermal lymphocytes demonstrated a CD4:CD8 ratio ≤1 : 1. Low background levels of the patient's previously identified MF/SS-associated TCR sequence(s) were demonstrated in 20/46 specimens analyzed by high-throughput sequencing of TCR. We conclude that MAR may demonstrate diverse histologic features. Findings that may distinguish MAR from MF/SS include the inverted or normalized CD4:CD8 ratio within intraepidermal lymphocytes and demonstration of absent or nondominant levels of disease-associated TCR sequences. Correlation with the clinical findings and immunohistochemical and molecular characterization of the patient's MF/SS before mogamulizumab, when possible, may facilitate recognition of MAR.

[Pattern analysis of inflammatory skin diseases according to A. B. Ackerman-always up to date]

The exact microscopic diagnosis of inflammatory skin diseases requires the linking of histopathological findings with clinical features. This is not easy when skin biopsies are rarely assessed and the terminology of dermatopathology and dermatology is itself unfamiliar.The infiltrates of almost all inflammatory skin diseases tend to show eight specific patterns in high magnification. By further classifying according to architectural and cytological features, a specific diagnosis can be made in most cases. At the same time, clinically suspected diagnoses are simply excluded or greatly reduced in number. This procedure, starting with the overview magnification and the recognition of clearly defined histomorphological features, corresponds to an algorithm.Another algorithmic approach uses histomorphological changes under high magnification. Here, "nonspecific" findings are added to the pattern analysis as a diagnostic vehicle.Occasionally, inflammatory skin diseases cannot be assessed conclusively with current modern methods. Such pathology reports should be written descriptively and possible differential diagnoses should be mentioned as notes. The report should be written in a language understandable to the clinician.Artificial intelligence, with its ability to transform and integrate extensive clinical as well as image data, will play an important role in the future of decision making, diagnosing, and personalizing medicine. In the field of pathology, it could be seen as a second opinion. It is important that physicians always contribute their opinion where important algorithmic decisions are made, such as in algorithm design, data quality, interpretation, action, and feedback.

Risk Factors for the Development of Psoriasis

Psoriasis is an immune-mediated genetic skin disease. The underlying pathomechanisms involve complex interaction between the innate and adaptive immune system. T cells interact with dendritic cells, macrophages, and keratinocytes, which can be mediated by their secreted cytokines. In the past decade, biologics targeting tumor necrosis factor-α, interleukin (IL)-23, and IL-17 have been developed and approved for the treatment of psoriasis. These biologics have dramatically changed the treatment and management of psoriasis. In contrast, various triggering factors can elicit the disease in genetically predisposed individuals. Recent studies suggest that the exacerbation of psoriasis can lead to systemic inflammation and cardiovascular comorbidity. In addition, psoriasis may be associated with other auto-inflammatory and auto-immune diseases. In this review, we summarize the risk factors, which can be divided into two groups (namely, extrinsic and intrinsic risk factors), responsible for the onset and exacerbation of psoriasis in order to facilitate its prevention.

Dermatologic Urgencies and Emergencies: What Every Pathologist Should Know

CONTEXT.—

Fatal dermatologic diseases and ones with high morbidity can occur in the inpatient setting. In such cases, prompt and accurate assessment of a bedside skin biopsy is required. This may be challenging for many pathologists who are not familiar with the complexity of skin pathology and skin terminology within the fields of dermatopathology and dermatology.

OBJECTIVE.—

To provide the pathologist with a practical, up-to-date, and "must-know" reference guide on dermatologic urgencies and emergencies from a real-world perspective, highlighting diagnostic pearls, diagnostic pitfalls, and commonly encountered practice gaps. This review will focus on key diseases with which every pathologist should be familiar, including angioinvasive fungal infections, Stevens-Johnson syndrome/toxic epidermal necrolysis, staph-scalded-skin syndrome, acute graft-versus-host disease, bullous pemphigoid, calciphylaxis, Sweet syndrome and its histiocytoid variant, pyoderma gangrenosum, and leukocytoclastic vasculitis, as well as those in their clinical and histopathologic differential.

DATA SOURCES.—

This review is based on peer-reviewed literature and our personal experiences with these diseases at major academic institutions, including one where a large number of stem cell transplants are performed. This review is unique as it represents collaborative expert opinion from both a dermatopathology and a dermatology standpoint.

CONCLUSIONS.—

This review outlines the critical role that the pathologist plays in the outcomes of patients with dermatologic urgencies and emergencies. Improved patient care will result from prompt and accurate histopathologic diagnoses as well as an open line of communication with the dermatologist.

Drug-induced psoriasis: clinical perspectives

Exposure to certain drugs can elicit an induction or exacerbation of psoriasis. Although well-conducted systematic studies on drug-related psoriasis are mostly lacking, traditionally strong associations have been documented for beta-blockers, lithium, antimalarial drugs such as (hydroxy)chloroquine, interferons, imiquimod, and terbinafine. More recently, new associations have been reported for monoclonal antibody- and small-molecule-based targeted therapies used for oncological and immunological indications, such as tumor necrosis factor-alpha antagonists and anti-programmed cell death protein 1 immune checkpoint inhibitors. Recognizing potential drug-related psoriasis is of clinical relevance to allow an optimal management of psoriasis. However, in clinical practice, identifying medication-related exacerbations and induction of psoriasis can be challenging. The clinical and histopathological features of drug-provoked psoriasis may differ little from that of “classical” nondrug-related forms of psoriasis. In addition, the latency period between start of the medication and onset of psoriasis can be significantly long for some drugs. Assessment of the Naranjo adverse drug reaction probability scale could be used as a practical tool to better differentiate drug-related psoriasis. The first step in the management of drug-related psoriasis is cessation and replacement of the offending drug when deemed clinically possible. However, the induced psoriasis skin lesions may persist after treatment withdrawal. Additional skin-directed treatment options for drug-related psoriasis follows the conventional psoriasis treatment guidelines and includes topical steroids and vitamin D analogs, ultraviolet phototherapy, systemic treatments, such as acitretin, methotrexate, and fumaric acid esters, and biological treatments.

Adverse Medication Reactions

Cutaneous adverse drug reactions (ADRs) are among the most frequent adverse reactions in patients receiving drug therapy. They have a broad spectrum of clinical manifestations, are caused by various drugs, and result from different pathophysiological mechanisms. Hence, their diagnosis and management is challenging.

Severe cutaneous ADRs comprise a group of diseases with major morbidity and mortality, reaching 30 % mortality rate in cases of Toxic Epidermal Necrolysis.

This chapter covers the terminology, epidemiology, pathogenesis and classification of cutaneous ADR, describes the severe cutaneous ADRs and the clinical and laboratory approach to the patient with cutaneous ADR and presents the translation of laboratory-based discoveries on the genetic predisposition and pathogenesis of cutaneous ADRs to clinical management guidelines.

Granulomatous & histiocytic dermatitides

Granulomas of the skin may be classified in several ways. They are either infectious or non-infectious in character, and they contain areas of necrobiosis or necrosis, or not. Responsible infectious agents may be mycobacterial, fungal, treponemal, or parasitic organisms, and each case of granulomatous dermatitis should be assessed histochemically for those microbes. In the non-infectious group, examples of necrobiotic or necrotizing granulomas include granuloma annulare; necrobiosis lipoidica; rheumatoid nodule; and lupus miliaris disseminates faciei. Non-necrobiotic/necrotizing and non-infectious lesions are exemplified by sarcoidosis; foreign-body reactions; Melkersson-Rosenthal syndrome; Blau syndrome; elastolytic granuloma; lichenoid and granulomatous dermatitis; interstitial granulomatous dermatitis; cutaneous involvement by Crohn disease; granulomatous rosacea; and granulomatous pigmented purpura. Histiocytic dermatitides that do not feature granuloma formation are peculiar reactions to infection, such as cutaneous malakoplakia; leishmaniasis; histoplasmosis; lepromatous leprosy; rhinoscleroma; lymphogranuloma venereum; and granuloma inguinale.

Granulomatous Drug Eruptions

Granuloma formation is usually regarded as a means of defending the host from persistent irritants of either exogenous or endogenous origin. Noninfectious granulomatous disorders of the skin encompass a challenging group of diseases owing to their clinical and histologic overlap. Drug reactions characterized by a granulomatous reaction pattern are rare, and defined by a predominance of histiocytes in the inflammatory infiltrate. This review summarizes current knowledge on the various types of granulomatous drug eruptions, focusing on the 4 major types: interstitial granulomatous drug reaction, drug-induced accelerated rheumatoid nodulosis, drug-induced granuloma annulare, and drug-induced sarcoidosis.

Eczema-Like Psoriasiform Skin Reaction due to Brazilian Keratin Treatment

The use of formaldehyde and formaldehyde releasers in hair-straightening formulations started in Rio de Janeiro in 2003. The technique is known as BKT, Brazilian keratin treatment. The aim of this study was to analyze the types of skin reactions presented by patients due to BKT. We describe 7 patients with severe erythema and scurf on the scalp which developed shortly after BKT. The lesions were eczema-like psoriasiform, located mainly on the scalp. Some patients also developed eczema-like lesions and pustules on the face, neck, upper arms, and upper trunk. Dermatoscopic findings included erythema, perifollicular and interfollicular scurf. The peripilar desquamation resembled the outer skin of an onion bulb. Scalp biopsies revealed psoriasiform and spongiotic psoriasiform patterns, one of them similar to anti-TNFα biologic drug psoriasiform alopecia. The possible consequences of the absorption of formaldehyde by hairdressers or clients are still to be verified by the scientific community; however, the skin and scalp reactions observed in our cases suggest a drug reaction phenomenon and not only eczemas of irritant or allergic origin.

Skin Biopsy, the Allergists' Tool: How to Interpret a Report

Inflammatory dermatoses are frequently encountered by the allergist, and histologic evaluation achieved through skin biopsy can be of tremendous value clinically. There is no substitute for a thorough history and physical exam; however, the skin biopsy is a simple, in-office procedure with little risk of complication that can provide invaluable information when a diagnosis is uncertain. Histopathologically, many inflammatory eruptions can look similar or overlap, but information provided by the dermatopathologist can help the clinician render or refine the clinical diagnosis and guide management. This review will discuss descriptive elements contained in the pathology report to provide a framework that can be used by the allergist to comfortably and confidently diagnose inflammatory dermatologic conditions.

Drug-induced skin reactions: a pathologist viewpoint

Cutaneous drug reactions are common adverse effects that occur in about 2-3% of the hospitalized patients. They have both immunologic and non-immunologic underlying mechanisms. These reactions are clinically and histologically similar to dermatoses. Their significant clinical indicators include: history of drug intake, atypical clinical features and improvement after cessation of the offending drugs. Their diagnostic histological clues include the presence of mixed histological patterns, apoptotic keratinocytes, eosinophils (dermis and epidermis), papillary dermal edema and extravasations of erythrocytes. However, no single clinical or histological feature is specific of drug eruptions. This work attempts to classify the histomorphologic reactions to various drugs in defined categories for assistance in morphologic diagnosis.

Levetiracetam induced psoriasiform drug eruption: a rare case report

Levetiracetam (LEV) is an established second generation anti-epileptic drug and LEV associated severe cutaneous reactions are rare. Here we report the case of psoriasiform drug eruption in a patient with newly diagnosed epilepsy who had been treated with levetiracetam. To our knowledge this is the first report of a patient with a psoriasiform eruption that appeared after the administration of LEV.

Drug-induced skin reactions: a 2-year study

Background

The aim of this study was to analyze the clinical characteristics of patients with adverse cutaneous drug reactions, which occur when a medicinal product results in cutaneous morbidity.

Methods

The study included 308 patients who were diagnosed as having an adverse cutaneous drug reaction during the study period (2007–2009). In 84 cases, histopathologic examination of skin biopsies were also performed.

Results

Patients with drug reactions were found to be more commonly female (63%) than male (37%). Beta-lactam antibiotics were found to be the most frequent cause of adverse cutaneous drug reactions (42.7%), followed by non-steroidal anti-inflammatory drugs (16.5%). Acute urticaria was the most common clinical presentation (59.2%) followed by fixed drug eruptions (18.5%), and maculopapular eruptions (14.9%).

Conclusion

Adverse cutaneous drug reactions in our study population were mainly induced by beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The most common forms of cutaneous adverse drug reactions were found to be acute urticaria, fixed drug eruptions, and maculopapular rashes.

A review of cutaneous drug eruptions

Cutaneous drug eruptions can range from an asymptomatic rash to a life-threatening emergency. Because of the high frequency, morbidity, and potential mortality associated with drug eruptions, patients with possible drug reactions should promptly be recognized, worked up, and treated. Drug reactions are common in the elderly population due to age-related alterations in metabolism, excretion of medications, and polypharmacy. This review discusses the epidemiology, pathogenesis, clinical presentation, diagnosis, and management of drug eruptions that providers commonly encounter in the care of the geriatric population. An algorithm for an approach to patients with a suspected drug eruption is presented.

Mimics of cutaneous lymphoma: report of the 2011 Society for Hematopathology/European Association for Haematopathology workshop

The Society for Hematopathology and European Association for Haematopathology workshop, from October 27 to 29, 2011, in Los Angeles, CA, exhibited many exemplary skin biopsy specimens with interesting inflammatory changes mimicking features of cutaneous lymphoma. This article reviews features observed in cutaneous lymphoid hyperplasia, cutaneous drug reactions, lupus-associated panniculitis, pityriasis lichenoides, hypereosinophilic syndrome, histiocytic necrotizing lymphadenitis, traumatic ulcerative granuloma with stromal eosinophils, and pigmented purpuric dermatosis, as well as a brief review of the pertinent literature and discussion of submitted conference cases. For the pathologist, it is important to be aware of diagnostic pitfalls as well as the limitations of ancillary testing (eg, clonality studies). Finally, correlation with total clinical information, good communication with clinical colleagues, close clinical follow-up with rebiopsy, and prudent use of laboratory studies are vital and will likely offer the best path toward a correct diagnosis.

Lichen planus-like drug eruptions due to β-blockers: a case report and literature review

Lichen planus-like drug eruptions (LDE) can appear similar or identical to idiopathic lichen planus. We present a 45-year-old man with a widespread, violaceous, papular, generalized exanthema with histologic features of a lichenoid reaction, which subsequently resolved with the cessation of labetatol. We found 29 cases of previously reported β-adrenoceptor antagonist (β-blocker)-associated LDE. This is a relatively rare complication that may present as classic lichenoid papules indistinguishable from lichen planus and has a predilection for the limbs, chest, back, and oral mucosa. Histologically, there is a lichenoid infiltrate often with eosinophils. LDE may be due to drug cross-reactivity or as a result of a suppressed skin adrenergic system. Multiple potential medications in case studies and the inability to differentiate LDE from idiopathic lichen planus in cross-sectional association studies make any conclusive analysis difficult.

Definitions and mechanisms of drug hypersensitivity

Adverse drug reactions are a difficult problem faced by clinicians in everyday practice. The mechanisms of drug hypersensitivity are not well understood. This is reflected by difficulties in their classification, which is mainly based upon the current knowledge of immunologic and nonimmunologic mechanisms, onset of symptoms (immediate or nonimmediate) and morphology. For the individual patient, the correct diagnosis and classification is important because strict avoidance of the offending drug might be of vital importance. Considerable experience is required to guide management, to interpret results of investigations and to undertake drug challenges. This article summarizes the current knowledge regarding definitions and mechanisms. However, the field of drug hypersensitivity is rapidly expanding. Modern drugs such as biological agents bare hypersensitivity risks that are potentially mediated by, so far, unknown mechanisms.

Psoriasiform eruption triggered by a dipeptidyl peptidase IV inhibitor

Psoriatic patients have a higher prevalence of diabetes mellitus type 2 (DM). Since dipeptidyl peptidase IV (DPP-IV) dysregulation is present in DM and psoriasis, DPP-IV inhibitors have been proposed as therapeutic agents for both conditions. We report a psoriasiform eruption induced by sitagliptin, a DPP-IV inhibitor. The role of DPP-IV in the pathogenesis of DM is well established; however data on psoriatic patients is contradictory. More studies are required to elucidate the effect of DPP-IV inhibitors and their relationship with DM and psoriasis.

Histopathology of drug eruptions - general criteria, common patterns, and differential diagnosis

Drug eruptions are among the most common inflammatory diseases of the skin and also among those biopsied most often. Yet, the value of histopathologic examination of drug eruptions has often been disputed. One reason is that the spectrum of histopathologic changes in drug eruptions is broad. Nevertheless, each histopathologic pattern assumed by drug eruptions has a limited number of differential diagnoses, and numerous criteria and clues are available to distinguish drug eruptions from other diseases associated with those patterns. By recognition of common patterns, consideration of differential diagnoses, and attention to distinct clues, a histopathologic diagnosis of drug eruption can usually be made with confidence.

Cutaneous leukocytoclastic vasculitis due to anti-tuberculosis medications, rifampin and pyrazinamide

Anti-tuberculosis drugs frequently result in cutaneous adverse reactions, including pruritus, maculopapular exanthems, and urticaria. However, anti-tuberculosis drug-associated cutaneous leukocytoclastic vasculitis (CLV) has been rarely reported. We describe a case of CLV induced by rifampin and pyrazinamide. A 38-year-old male had been diagnosed with pulmonary tuberculosis two months ago and then he started standard anti-tuberculosis therapy with isoniazid, rifampin, ethambutol, and pyrazinamide. Purpuric lesions developed in the extremities after 1.5 months of anti-tuberculosis medication; the lesions progressively spread over the entire body. Histopathology of the purpuric skin lesion was consistent with leukocytoclastic vasculitis. The skin lesion improved after cessation of anti-tuberculosis medications and treatment with oral corticosteroids and antihistamines. Anti-tuberculosis drugs were rechallenged one at a time over 3 days. Purpura recurred on the right forearm and forehead after taking 300 mg of rifampin. The skin lesion disappeared after taking oral prednisolone. Finally, 1,500 mg of pyrazinamide was readministrated, and then purpuric lesions recurred on both forearms. This report describes a case of leukocytoclastic vasculitis secondary to rifampin and pyrazinamide therapy.