Lichenoid drug reaction to antituberculosis drugs treated through with topical steroids and phototherapy

HIV-associated photodermatitis in African populations

Photosensitive dermatoses are seen in 5% of HIV-infected persons. These include drug- and chemical-induced photoallergic and phototoxic reactions, chronic actinic dermatitis of HIV, photo lichenoid drug eruptions, and porphyria. Data on photodermatitis in HIV are limited to case reports and series. The pathogenesis is not completely understood and includes a th2 phenotype in HIV which results in impaired barrier function and resultant allergen sensitisation as well as immune dysregulation. The objective of this manuscript is to review the literature on the clinical phenotype, pathogenesis, role of photo and patch testing, outcomes, and treatment of photodermatitis in HIV in an African population.

IFN-γ ELISpot in Severe Cutaneous Adverse Reactions to First-Line Antituberculosis Drugs in an HIV Endemic Setting

Severe cutaneous adverse reactions related to first-line antituberculosis drugs are associated with high mortality and long-term morbidity. Oral sequential drug challenge, as a form of drug provocation testing, helps to salvage therapy by identifying culprit drugs but is associated with risk and is costly. IFN-γ enzyme-linked immune absorbent spot (ELISpot), an adjunctive in vitro diagnostic tool, may help to guide risk-stratification approaches. To determine the diagnostic accuracy of IFN-γ ELISpot against full-dose sequential drug challenge, we analyzed samples collected prospectively at multiple time points in 32 patients with first-line antituberculosis drug‒associated severe cutaneous adverse reaction (81% HIV infected, 25 with drug reaction with eosinophilia and systemic symptoms, and 7 with Stevens‒Johnson syndrome/toxic epidermal necrolysis). Sensitivity of IFN-γ ELISpot was 33% (4 of 12), 13% (1 of 8), 11% (1 of 9), and 0% (0 of 4) for rifampicin, isoniazid, pyrazinamide, and ethambutol, respectively (positivity threshold ≥50 spot forming units/million cells). Specificity was 100% for all the four drugs. Rifampicin IFN-γ ELISpot sensitivity increased to 58% (7 of 12) if a threshold of 20 spot forming units was used and to 75% (3 of 4) when restricted to samples <12 weeks after acute severe cutaneous adverse reaction event; specificity remained 100% for both. IFN-γ ELISpot offers adequate risk stratification of rifampicin severe cutaneous adverse reaction using acute samples and lowered threshold for positivity. Given the low sensitivity of IFN-γ ELISpot for other first-line antituberculosis drugs, additional optimization is needed to improve risk-stratification potential.

Recognizing Drug Hypersensitivity in Pigmented Skin

The imagery of pigmented skin is underrepresented in teaching materials such as textbooks, journals, and online references, and this has resulted in poorer diagnostic and management outcomes of skin pathology, including delayed cutaneous drug hypersensitivity reactions. In this review, we use clinical images to highlight factors that impact clinical presentations and sequelae of drug hypersensitivity reactions in pigmented skin compared with nonpigmented skin. We describe clinical features in some anatomic sites that aid diagnosis or are associated with more severe sequelae. Finally, we discuss strategies that may aid the diagnosis and management of these reactions in pigmented skin.

Fixed drug eruptions, bullous drug eruptions, and lichenoid drug eruptions

Drug reactions are among the most common reasons for inpatient dermatology consultation. These reactions are important to identify because discontinuation of the offending agent may lead to disease remission. With the rising use of immunomodulatory and targeted therapeutics in cancer care and the increased incidence in associated reactions to these drugs, the need for accurate identification and treatment of such eruptions has led to the development of the "oncodermatology" subspecialty of dermatology. Immunobullous drug reactions are a dermatologic urgency, with patients often losing a significant proportion of their epithelial barrier; early diagnosis is critical in these cases to prevent complications and worsening disease. Lichenoid drug reactions have myriad causes and can take several months to occur, often leading to difficulties identifying the offending drug. Fixed drug eruptions can often mimic other systemic eruptions, such as immunobullous disease and Stevens-Johnson syndrome, and must be differentiated from them for effective therapy to be initiated. We review the clinical features, pathogenesis, and treatment of immunobullous, fixed, and lichenoid drug reactions with attention to key clinical features and differential diagnosis.

Lichenoid drug reaction due to anti-tubercular therapy presenting as erythroderma

First-line anti-tubercular therapy (ATT) is very effective in management of tuberculosis and is usually well tolerated. Varied spectrum of cutaneous adverse drug reactions is associated with ATT, of which lichenoid drug eruption (LDR) constitutes approximately 10% of the cases. However, LDR presenting as erythroderma is very rare. Here, we report a case of exfoliative dermatitis secondary to LDR which developed after 5 months of ATT.

Severe Delayed Cutaneous and Systemic Reactions to Drugs: A Global Perspective on the Science and Art of Current Practice

Most immune-mediated adverse drug reactions (IM-ADRs) involve the skin, and many have additional systemic features. Severe cutaneous adverse drug reactions (SCARs) are an uncommon, potentially life-threatening, and challenging subgroup of IM-ADRs with diverse clinical phenotypes, mechanisms, and offending drugs. T-cell-mediated immunopathology is central to these severe delayed reactions, but effector cells and cytokines differ by clinical phenotype. Strong HLA-gene associations have been elucidated for specific drug-SCAR IM-ADRs such as Stevens-Johnson syndrome/toxic epidermal necrolysis, although the mechanisms by which carriage of a specific HLA allele is necessary but not sufficient for the development of many IM-ADRs is still being defined. SCAR management is complicated by substantial short- and long-term morbidity/mortality and the potential need to treat ongoing comorbid disease with related medications. Multidisciplinary specialist teams at experienced units should care for patients. In the setting of SCAR, patient outcomes as well as preventive, diagnostic, treatment, and management approaches are often not generalizable, but rather context specific, driven by population HLA-genetics, the pharmacology and genetic risk factors of the implicated drug, severity of underlying comorbid disease necessitating ongoing treatments, and cost considerations. In this review, we update the basic and clinical science of SCAR diagnosis and management.

Lichen planus and other lichenoid dermatoses: Kids are not just little people

Lichenoid dermatoses, a group of inflammatory skin conditions with characteristic clinical and histopathologic findings, range from common to rare. Classic lichen planus typically presents as pruritic, polygonal, violaceous flat-topped papules and plaques; many variants in morphology and location also exist. Other lichenoid dermatoses share similar clinical presentations and histopathologic findings. These include lichenoid drug eruption, lichen planus-like keratosis, lichen striatus, lichen nitidus, and keratosis lichenoides chronica. Epidemiologic characteristics vary among each lichenoid disorder. While classic lichen planus is considered a disease of adults, other lichenoid dermatoses may be more common in younger populations. The literature contains an array of reports on the variations in presentation and successful management of lichen planus and lichenoid dermatoses among diverse populations. Familiarity with the characteristics of each lichenoid dermatosis, rare or common within each patient population, is key to accomplishing timely recognition and effective management.

Adverse drug events in the oral cavity

Adverse reactions to medications are common and may have a variety of clinical presentations in the oral cavity. Targeted therapies and the new biologic agents have revolutionized the treatment of cancers, autoimmune diseases, and inflammatory and rheumatologic diseases but have also been associated with adverse events in the oral cavity. Some examples include osteonecrosis, seen with not only bisphosphonates but also antiangiogenic agents, and the distinctive ulcers caused by mammalian target of rapamycin inhibitors. As newer therapeutic agents are approved, it is likely that more adverse drug events will be encountered. This review describes the most common clinical presentations of oral mucosal reactions to medications, namely, xerostomia, lichenoid reactions, ulcers, bullous disorders, pigmentation, fibrovascular hyperplasia, white lesions, dysesthesia, osteonecrosis, infection, angioedema, and malignancy. Oral health care providers should be familiar with such events, as they will encounter them in their practice.

Lichenoid drug reaction to isoniazid presenting as exfoliative dermatitis in a patient with acquired immunodeficiency syndrome

Human immunodeficiency virus-infected patients are at increased risk of drug reactions because of immune dysregulation and multiple drug intake. Lichenoid drug reactions to isoniazid have been reported previously in the literature. However, for lichenoid drug reaction to isoniazid to be so extensive to present as exfoliative dermatitis is rare. We report here a rare case of lichenoid drug reaction to isoniazid presenting as exfoliative dermatitis in a patient with acquired immunodeficiency syndrome.

Clinical presentations of severe cutaneous drug reactions in HIV-infected Africans

Sub-Saharan Africa is the epicenter of the HIV pandemic and HIV-infected people are more susceptible to inflammatory dermatoses, infections, and drug eruptions. Many of the drugs used for HIV-associated opportunistic infections are associated with a higher incidence of drug-related toxicities and drug interactions. This article discusses the epidemiology, pharmacogenetics, and clinical features of idiosyncratic drug reactions in HIV-infected Africans. Special considerations in this population, including immune reconstitution inflammatory syndrome, multiple drug hypersensitivity syndrome, drug reactions in pregnancy, drug rechallenge in lichenoid drug eruptions, and anxiety/depression after cutaneous adverse drug reactions, are also briefly discussed.