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

Case report: Generalized bullous fixed drug eruption mimicking epidermal necrolysis

Generalized bullous fixed drug eruption (GBFDE) is the most severe form of fixed drug eruption and can be misdiagnosed as epidermal necrolysis (EN). We report the case of a 42-year-old male patient presenting with more than 50% skin detachment without defined areas of exanthema or erythema and a history of one prior event of EN caused by acetaminophen (paracetamol), allopurinol, or amoxicillin 1.5 years ago. The initial diagnosis was GBFDE or EN. The histology of a skin biopsy was unable to distinguish between the two diseases. The course of the disease, the later clinical presentation, and the medical and medication history, however, were in favor of a diagnosis of GBFDE with two potentially culprit drugs: metamizole and ibuprofen. Moxifloxacin, enoxaparin sodium, hydromorphone, and insulin human were administered concomitantly, which makes them suspicious as well. Unfortunately, the patient received an additional dose of metamizole, one of the possible causative drugs, and he developed another bullous reaction within 1 month. This led to the diagnosis of GBFDE due to metamizole. This report highlights the challenges of distinguishing two rare diseases and elucidates the importance of distinct clinical presentation and detailed medication history.

Hypopigmented penile fixed drug eruption

Fixed drug eruptions (FDE) are typically associated with residual hyperpigmentation or non-pigmenting lesions. There is no distinctive histopathological feature; though, drug provocation tests (DPT) can be confirmatory within 7 days. We describe a patient with penile FDE associated with residual hypopigmentation, a prolonged refractory period to DPT and recurrent meatal stenosis.

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.

Drug-Induced vs. Viral Maculopapular Exanthem—Resolving the Dilemma

Maculopapular exanthem is a commonly encountered presentation in routine clinical practice, and differentiation between its two most common etiologies, i.e., viral- and drug-induced, often poses a diagnostic dilemma. Clinical, hematological and biochemical investigations are seldom reliable in distinguishing between a drug reaction and a viral exanthem. Certain key histopathological features such as the presence of a moderate degree of spongiosis, extensive basal cell damage with multiple necrotic keratinocytes and dermal infiltrate rich in eosinophils or lymphocytes and histiocytes may favor a drug exanthem, while distinctive epidermal cytopathic changes and lymphocytic vasculitis point towards a viral etiology. Similarly, notable immunohistochemical markers such as IL-5, eotaxin and FAS ligand may support a diagnosis of a drug-induced maculopapular eruption. Histopathological and immunohistochemical evaluations may help in distinguishing between the two etiologies when faced with a clinical overlap, especially in patients on multiple essential drugs when drug withdrawal and rechallenge is not feasible.

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.

Interstitial Granulomatous Drug Reaction to Ustekinumab

Interstitial granulomatous drug reaction (IGDR) is a distinct inflammatory process that often presents as annular, violaceous plaques distributed on the extremities, proximal trunk, and intertriginous areas. The list of drugs implicated for inciting IGDR is growing, but most prominently includes ACE inhibitors, antihistamines, beta-blockers, antidepressants, and anticonvulsants. Ustekinumab is a human monoclonal antibody that targets inflammatory cytokines IL-12 and IL-23 and has been have shown to be effective in treating IGDR. However, we present a case that suggests ustekinumab can also act as an inciting agent for IGDR.

A Review of Fixed Drug Eruption with a Special Focus on Generalized Bullous Fixed Drug Eruption

Fixed drug eruption (FDE) is a cutaneous adverse drug reaction characterized by the onset of rash at a fixed location on the body each time a specific medication is ingested. With each recurrence, the eruption can involve additional sites. Lesions can have overlying vesicles and/or bullae, and when they cover a significant percentage of body surface area, the eruption is referred to as generalized bullous fixed drug eruption (GBFDE). Due to the widespread skin denudation that can be seen in this condition, GBFDE may be confused clinically with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). While treatments described for GBFDE include supportive care, topical and/or systemic steroids, and, recently, cyclosporine, the mainstay of management involves identifying and discontinuing the causative drug. This review article will provide an overview of FDE with an emphasis on its generalized bullous variant.

Are apoptosis-determining techniques useful to establish an early diagnosis of acute graft-vs-host disease in pediatric patients under treatment with multiple drugs?

BACKGROUND

There are no pathognomonic histopathological features to distinguish acute graft-vs-host disease (aGVHD) from skin drug reactions (SDRs) in pediatric patients with multiple drug regimens that have received blood transfusions and/or transplants. We aimed to determine if the addition of apoptosis markers is helpful to distinguish aGVHD from SDRs in these patients.

METHODS

Skin biopsy specimens from patients with a clinical diagnosis of aGVHD or SDRs were evaluated for the presence of apoptotic bodies, satellitosis, interface damage, vasculitis, and inflammatory infiltrate on H&E stain. Information was completed with apoptotic markers (transferase-mediated dUTP nick end-labeling [TUNEL], bcl-2, and caspase-3).

RESULTS

The skin biopsy specimens of 32 patients with aGVHD and 11 with SDRs were included for study. Only the number of apoptotic keratinocytes per 10 high-power fields (hpf) showed a significant difference between both groups (P = 0.02); the presence of ≥4 apoptotic keratinocytes per 10 hpf was identified as the optimal cut-off point to discriminate aGVHD from SDRs. No SDRs cases had follicular apoptotic cells. TUNEL, bcl-2, and caspase-3 determination showed no difference between both groups.

CONCLUSIONS

The presence of ≥4 apoptotic keratinocytes per 10 hpf (in aGVHD) and the absence of follicular apoptotic cells (in SDRs) might be a useful marker to distinguish between them.

Clinical and histopathological characterization of paradoxical head and neck erythema in patients with atopic dermatitis treated with dupilumab: a case series

Dupilumab is the first biologic registered for the treatment of atopic dermatitis (AD). We report on seven patients with AD presenting with a paradoxical head and neck erythema that appeared 10-39 weeks after the start of dupilumab treatment. The patients presented with a relatively sharply demarcated, patchy erythema in the head and neck area that showed no or less scaling compared with their usual eczema. Only one patient experienced symptoms of itch and burning, although this was notably different from his pre-existent facial AD. Except for a notable 'red face', eczema on other body parts had greatly improved in six of the seven patients, with a mean numerical rating scale for treatment satisfaction of 9 out of 10 at the time of biopsy. Treatment of the erythema with topical and systemic drugs was unsuccessful. Despite the presence of this erythema, none of our patients discontinued dupilumab treatment. Lesional skin biopsies showed an increased number of ectatic capillaries, and a perivascular lymphohistiocytic infiltration in all patients. In addition, epidermal hyperplasia with elongation of the rete ridges was observed in four patients, resembling a psoriasiform dermatitis. Additional immunohistochemical stainings revealed increased numbers of plasma cells, histiocytes and T lymphocytes. Interestingly, spongiosis was largely absent in all biopsies. We report on patients with AD treated with dupilumab developing a paradoxical erythema in a head and neck distribution. Both clinically and histopathologically we found a heterogeneous response, which was most suggestive of a drug-induced skin reaction.

Drugs as a Frequent Cause of Acute Rash in Patients after CD34+-Selected Peripheral Blood Stem Cell Transplantation

Although histopathological differences have been reported between acute graft-versus-host disease (aGVHD) rash and non-aGVHD rash in CD34+-selected peripheral blood stem cell transplantation (PBSCT) recipients, skin biopsy alone is usually insufficient to determine rash etiology. As such, distinguishing inflammatory non-aGVHD rashes, such as drug eruptions, from cutaneous aGVHD after CD34+-selected PBSCT remains challenging and relies on clinical presentation. This study aimed to identify etiologies of skin rash in the first year after CD34+-selected PBSCT and to assess whether laboratory serologic markers, transplant characteristics, and rash morphology and symptomatology aid in differentiation of cutaneous aGVHD rash versus non-aGVHD rash. We conducted a retrospective study of 243 adult patients who underwent CD34+-selected PBSCT at Memorial Sloan Kettering Cancer Center between 2008 and 2011. Among this cohort of transplant recipients, only 43 patients (17.7%) developed cutaneous aGVHD. A total of 152 patients (63%) were identified with rash within 1 year after PBSCT. The proportion of patients who experienced peripheral eosinophilia was not different between those with an aGVHD versus non-aGVHD rash (P ≥ .90), nor when stratified by CD34+ selection method (Isolex, P = .70; CliniMACS, P≥ .90). The proportion of patients with pruritus was also not different between those with an aGVHD rash versus non-aGVHD rash (P= .20), or when stratified by CD34+ selection modality (Isolex, P = .20; CliniMACS, P = .50). The most common cause of non-aGVHD rash among those with a clear etiology was drug (39% of Isolex; 26% of CliniMACS). Single drug culprits were identified in 51% of drug rashes. The most commonly reported offending agents included antibiotics, keratinocyte growth factor, chemotherapy, and recombinant glycosylated human IL-7.

Contrast-induced generalized bullous fixed drug eruption resembling Stevens-Johnson syndrome

A 59-year-old woman with end-stage renal disease presented for suspected Stevens-Johnson syndrome that was ultimately diagnosed as generalized bullous fixed drug eruption (GBFDE) secondary to the administration of iodinated nonpolar radiocontrast. The patient had three previous episodes of a generalized bullous eruption after a thrombectomy, fistulogram, and an arteriovenous fistula revision, all requiring radiocontrast administration. Biopsies taken after previous eruptions demonstrated full-thickness epidermal necrosis, and she was diagnosed with Stevens-Johnson syndrome thought to be due to allopurinol. However, against medical advice she continued taking allopurinol and remained asymptomatic until the current presentation. Based on the clinical appearance and time frame of the eruptions, the patient was diagnosed with GBFDE due to radiocontrast. GBFDE, a rare variant of a fixed drug eruption, can be misdiagnosed as Stevens-Johnson syndrome due to their overlapping features of drug-induced whole-body blisters and variable degrees of epidermal necrosis.

[Immunopathology of cutaneous drug eruptions]

BACKGROUND

Adverse drug reactions (ADR) are common and may present clinically and histologically in a very heterogeneous manner. The pathophysiological understanding about causal immunological and non-immunological events has developed significantly over the past years. Skin and mucosa are commonly affected and are prone for histopathological examination. Certain groups of drugs such as immune checkpoint inhibitors may cause specific adverse reactions.

OBJECTIVES

To provide a comprehensive overview of the complex immunological events and the most common dermatohistopathological findings of cutaneous adverse drug reactions.

MATERIAL AND METHODS

Review of the literature (PubMed), own study data and pictures obtained via routine diagnostics at the University of Bonn.

RESULTS AND DISCUSSION

Drugs may induce a wide range of skin reactions displaying a diversity of cutaneous inflammatory patterns. Histopathological clues for drug eruptions may be: eosinophils, lichenoid infiltrate and isolated keratinocytic apoptosis; a thorough medical history and correlation of clinical findings and dermatohistopathology are most important. Knowledge of typical adverse reactions to checkpoint inhibitors and their management is of great clinical interest as their use is rising steadily.

[Systematic analysis of pathological changes in inflammatory dermatoses : New dermatopathological criteria and algorithms]

Standardized analysis of histological findings in a routinely stained section without knowledge of the clinical picture ("blind fashion") allows an objective assessment of the pathological changes. In inflammatory dermatoses diagnostic algorithms and criteria have been proven. They follow defined main inflammatory patterns, the composition of the inflammatory infiltrate and additional criteria. Taking into account the stage of development and the possibility of collision phenomena, this approach will give a histological diagnosis, or at least a limited number of differential diagnoses. However, the final diagnosis always results from the synopsis of the clinical picture and additional parameters. The modern development of algorithms and new histological criteria are outlined in autoimmune dermatoses, autoinflammatory syndromes, drug reactions and genodermatoses.

Immunohistopathological Findings of Severe Cutaneous Adverse Drug Reactions

Diagnosis of severe cutaneous adverse drug reactions should involve immunohistopathological examination, which gives insight into the pathomechanisms of these disorders. The characteristic histological findings of erythema multiforme (EM), Stevens–Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN) provide conclusive evidence demonstrating that SJS/TEN can be distinguished from EM. Established SJS/TEN shows full-thickness, extensive keratinocyte necrosis that develops into subepidermal bullae. Drug-induced hypersensitivity syndrome (DIHS) and exanthema in drug reaction with eosinophilia and systemic symptoms (DRESS) each display a variety of histopathological findings, which may partly correlate with the clinical manifestations. Although the histopathology of DRESS is nonspecific, the association of two or more of the four patterns—eczematous changes, interface dermatitis, acute generalized exanthematous pustulosis- (AGEP-) like patterns, and EM-like patterns—might appear in a single biopsy specimen, suggesting the diagnosis and severe cutaneous manifestations of DRESS. Cutaneous dendritic cells may be involved in the clinical course. AGEP typically shows spongiform superficial epidermal pustules accompanied with edema of the papillary dermis and abundant mixed perivascular infiltrates. Mutations in IL36RN may have a definite effect on pathological similarities between AGEP and generalized pustular psoriasis.

Rivaroxaban-Induced Hypersensitivity Syndrome

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Debilitating Skin Toxicity Associated with Pembrolizumab Therapy in an 81-Year-Old Female with Malignant Melanoma

Frequently described immune-mediated adverse effects of immune therapy include dermatological complications, hepatitis, colitis, pneumonitis, and endocrinopathies. As utilization of pembrolizumab and related agents continues to expand both in the available indications as well as duration of exposure, there remains a significant potential to uncover previously undescribed adverse events. From a dermatological standpoint, 39% of patients receiving pembrolizumab therapy experience some form of skin-related drug toxicity [Naidoo et al.: Ann Oncol 2015;26: 2375-2391]. We describe a case of pembrolizumab-induced disabling autoimmune ectodermal toxicity.