Cutaneous adverse effects of lithium: epidemiology and management

Molecular mechanisms and therapeutic potential of lithium in Alzheimer's disease: repurposing an old class of drugs

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and memory loss. Despite advances in understanding the pathophysiological mechanisms of AD, effective treatments remain scarce. Lithium salts, recognized as mood stabilizers in bipolar disorder, have been extensively studied for their neuroprotective effects. Several studies indicate that lithium may be a disease-modifying agent in the treatment of AD. Lithium's neuroprotective properties in AD by acting on multiple neuropathological targets, such as reducing amyloid deposition and tau phosphorylation, enhancing autophagy, neurogenesis, and synaptic plasticity, regulating cholinergic and glucose metabolism, inhibiting neuroinflammation, oxidative stress, and apoptosis, while preserving mitochondrial function. Clinical trials have demonstrated that lithium therapy can improve cognitive function in patients with AD. In particular, meta-analyses have shown that lithium may be a more effective and safer treatment than the recently FDA-approved aducanumab for improving cognitive function in patients with AD. The affordability and therapeutic efficacy of lithium have prompted a reassessment of its use. However, the use of lithium may lead to potential side effects and safety issues, which may limit its clinical application. Currently, several new lithium formulations are undergoing clinical trials to improve safety and efficacy. This review focuses on lithium's mechanism of action in treating AD, highlighting the latest advances in preclinical studies and clinical trials. It also explores the side effects of lithium therapy and coping strategies, offering a potential therapeutic strategy for patients with AD.

Triggers for the onset and recurrence of psoriasis: a review and update

Psoriasis is an immune-mediated inflammatory skin disease, involving a complex interplay between genetic and environmental factors. Previous studies have demonstrated that genetic factors play a major role in the pathogenesis of psoriasis. However, non-genetic factors are also necessary to trigger the onset and recurrence of psoriasis in genetically predisposed individuals, which include infections, microbiota dysbiosis of the skin and gut, dysregulated lipid metabolism, dysregulated sex hormones, and mental illness. Psoriasis can also be induced by other environmental triggers, such as skin trauma, unhealthy lifestyles, and medications. Understanding how these triggers play a role in the onset and recurrence of psoriasis provides insights into psoriasis pathogenesis, as well as better clinical administration. In this review, we summarize the triggers for the onset and recurrence of psoriasis and update the current evidence on the underlying mechanism of how these factors elicit the disease. Video Abstract.

Why Pharmacovigilance of Non-steroidal Anti-inflammatory Drugs is Important in India?

BACKGROUND

Non-steroidal Anti-Inflammatory Drugs (NSAIDs) are among the drugs that are most regularly administered to manage inflammation and pain. Over-the-Counter (OTC) NSAIDs are widely accessible, particularly in developing countries like India. This casual approach to using NSAIDs may operate as a magnet for NSAID-related adverse drug reactions (ADRs) among patients.

OBJECTIVES

As patients in India are less informed about the appropriate use of NSAIDs and consumption patttern, adverse drug reactions, and the importance of reporting ADRs, the current study's objective is to promote patient safety by using pharmacovigilance as a tool to educate patients.

METHODS

A targeted literature methodology was utilized to gather the data pertaining to NSAIDs, their ADRs and their pharmacovigilance. Different scientific databases, such as Science Direct, PubMed, Wiley Online Library, Springer, and Google Scholar, along with authentic textbooks, were explored as reference literature.

RESULTS

In general, NSAIDs consumption pattern depends upon the different age groups. Around 1.6 billion tablets of NSAIDs are consumed in India for ailments, such as headaches, arthritis, menstrual cramps, osteoarthritis, back pain, rheumatoid arthritis, gout, osteoporosis, tendinitis, cancer pain and chronic pain. Common ADRs of NSAIDs include nausea, vomiting, headache, gastritis, abdominal pain, and diarrhoea. Also, they can cause renal damage and cardiovascular problems if not consumed in a dose-dependent manner. However, Diclofenac and Ibuprofen have both been linked to depression and dementia. There have been reports of aplastic anaemia, agranulocytosis linked to phenylbutazone, Stevens-Johnson, and Lyell's syndrome linked to isoxicam and piroxicam, as well as the vulnerability of new-borns to Reye's syndrome after aspirin use. Lack of awareness, time constraints and unpredictability, poor training in ADRs identification, etc., are some of the reasons for the under-reporting of ADR of NSAIDs in India.

CONCLUSION

In order to rationally prescribe NSAIDs, it is essential to be aware of probable ADR's and establish prescription guidelines. Prescribers' behaviour can be changed toward excellent prescribing practices by conducting routine prescription assessments dealing with NSAIDs and providing feedback. In the near future, it will be critical to strengthen ADR data management and expand the reach of pharmacovigilance programs, ADR monitoring centers, and healthcare professionals' especially pharmacists' training in rural locations.

A Rare Phenomenon of Lithium-Associated Acne Inversa: A Case Series and Literature Review

Lithium use has been associated with dermatological issues, including psoriasis, folliculitis, and acneiform outbreaks. The lithium dosage and the therapeutic range of serum lithium levels are closely correlated with the frequency of cutaneous adverse effects. Lithium-induced acne inversa is a less well-known adverse effect, causing significant morbidity. Acne inversa (hidradenitis suppurativa) is a chronic inflammatory illness of the skin seen in the folds of the skin and face and distinguished by the presence of painful nodules and fistulas, as well as a propensity for tissue fibrosis. We report two cases of bipolar affective disorder who received long-term lithium treatment and experienced acne inversa during treatment, which subsided once the lithium was withdrawn.

Truncal Acne and Scarring: A Comprehensive Review of Current Medical and Cosmetic Approaches to Treatment and Patient Management

Acne vulgaris is one of the most common skin disorders worldwide. It typically affects skin areas with a high density of sebaceous glands such as the face, upper arms, chest, and/or back. Historically, the majority of research efforts have focused on facial acne vulgaris, even though approximately half of patients with facial lesions demonstrate truncal involvement. Truncal acne vulgaris is challenging to treat and poses a significant psychosocial burden on patients. Despite these characteristics, studies specifically examining truncal acne vulgaris are limited, with treatment guidelines largely derived from facial protocols. Therefore, truncal acne remains an understudied clinical problem. Here, we provide a clinically focused review on the epidemiology, evaluation, and available treatment options for truncal acne vulgaris. In doing so, we highlight knowledge gaps with the goal of spurring further investigation into the management of truncal acne vulgaris.

Pembrolizumab-induced follicular eruption and response to isotretinoin

Background: Pembrolizumab is a monoclonal antibody targeting PD-1. Folliculitis secondary to pembrolizumab has rarely been reported in the treatment of malignant melanoma. Case: A 49-year-old with a history of mild lower limb folliculitis developed metastatic malignant melanoma, and immunotherapy with pembrolizumab was initiated. Following 19 doses of pembrolizumab, a folliculocentric pustular eruption developed on the lower legs. Biopsy was consistent with folliculitis. Treatment with topical corticosteroids, high-dose prednisolone, lymecycline, clarithromycin, trimethoprim and clindamycin was unsuccessful. Pembrolizumab was stopped after 22 cycles, but the folliculitis persisted. Oral isotretinoin was required for disease control. Discussion: Drug-induced follicular eruptions have rarely been described with anti PD-1 therapy. Isotretinoin may be required to achieve remission.

Incidence and Factors Associated With Acne Among Transgender Patients Receiving Masculinizing Hormone Therapy

Importance

Acne is a common condition among transgender patients receiving masculinizing hormone therapy (MHT), but the incident risk and predictors of developing acne in this population have not yet been studied on a large scale.

Objective

To assess risk of acne among a large population of transgender patients receiving MHT and clinical risk factors for acne diagnosis.

Design, Setting, and Participants

A retrospective cohort study that included 988 patients who started MHT between January 1, 2014, and December 31, 2017, with at least 1 year of follow-up was performed. Data analysis was conducted from September 1 to 15, 2019. Data were obtained using electronic health records from a community health center serving the sexual and gender minority community. The population included every patient who began receiving MHT during the study period who was aged 18 years or older at the time of MHT initiation and whose assigned sex at birth was female.

Main Outcomes and Measures

The main outcome was acne defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification codes for acne. Overall prevalence and incidence proportions over 2 years after initiation of MHT were calculated. Baseline demographic and clinical characteristics were collected at the time of MHT initiation. A series of univariate analyses for all factors was calculated to test for an association with acne diagnosis, followed by multivariate analyses to test for independent predictors.

Results

For 988 patients (median age, 25.8 years; interquartile range, 20.8-28.2 years), there was an overall acne prevalence of 31.1% (n = 307). The 1-year post-MHT acne incidence proportion was 19.0% and the 2-year incidence proportion was 25.1%. A younger age at MHT initiation was associated with a higher likelihood of developing acne, with a median of 22.4 years (interquartile range, 19.7-25.6 years) among patients who developed acne vs 24.7 years (interquartile range, 21.3-29.4 years) among patients who did not (P = .002).

Conclusions and Relevance

Acne is a common condition among transgender patients on MHT, with a prevalence increasing from 6.3% to 31.1% following MHT initiation. Patients aged 18 to 21 years appear to be the most likely to develop acne after MHT initiation.

Emerging Pathophysiological Targets of Psoriasis for Future Therapeutic Strategies

Psoriasis is a chronic autoimmune skin disorder which involves complex interactions between genes, keratinocytes, T-cells and inflammatory cells. It affects 2-3% population worldwide. Molecular biology and cellular immunology of psoriasis, when linked with biotechnology and genetic studies can help researchers to understand the pathophysiology of psoriasis. T-cells activation, keratinocyte hyperproliferation, and angiogenesis are the core mechanisms entailed in the development of psoriasis lesion. Investigators are trying to overcome the challenges of complex pathophysiology pathways involved in this disorder. The different possible hypotheses for its pathophysiology such as growth factors, enzymes, inflammation, and genetic factors mediated pathophysiology have been described in the present review paper in detail. Clinically available drugs only control the symptoms of psoriasis but are not effective for the treatment of the disorder completely and are also associated with some side effects such as itching, renal disorders, hematologic, nonmelanoma skin cancer, pulmonary, gastrointestinal toxicity, etc. This paper made an effort to understand the pathophysiological targets, discuss the research done so far and the treatments available for the effective management of psoriasis.

A Review of Drugs that Induce or Exacerbate Psoriasis

Background

Psoriasis is a common disorder of the skin, immune system, and joints that is influenced by genetic and environmental factors. It can be aggravated or induced by drugs.

Objectives

To identify the major drugs implicated in inducing or exacerbating psoriasis and to discuss their characteristics.

Methods

We performed a PubMed literature search for reviews and case reports on drugs that exacerbate or induce psoriasis. Articles were screened by title and abstract and then examined for their findings and references.

Results

Drugs most often reported to exacerbate or induce psoriasis were β-blockers, lithium, synthetic antimalarials, nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, interferons, tetracyclines, tumor necrosis factor-α inhibitors, and steroid withdrawal.

Conclusions

Characterizing drugs that induce or exacerbate psoriasis by latency and type of psoriatic eruption can help guide clinical reasoning. Although a relatively uncommon occurrence, psoriatic lesions can be caused by drugs, allowing astute physicians to recognize and change their management plans accordingly.

Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder

The Canadian Network for Mood and Anxiety Treatments (CANMAT) previously published treatment guidelines for bipolar disorder in 2005, along with international commentaries and subsequent updates in 2007, 2009, and 2013. The last two updates were published in collaboration with the International Society for Bipolar Disorders (ISBD). These 2018 CANMAT and ISBD Bipolar Treatment Guidelines represent the significant advances in the field since the last full edition was published in 2005, including updates to diagnosis and management as well as new research into pharmacological and psychological treatments. These advances have been translated into clear and easy to use recommendations for first, second, and third- line treatments, with consideration given to levels of evidence for efficacy, clinical support based on experience, and consensus ratings of safety, tolerability, and treatment-emergent switch risk. New to these guidelines, hierarchical rankings were created for first and second- line treatments recommended for acute mania, acute depression, and maintenance treatment in bipolar I disorder. Created by considering the impact of each treatment across all phases of illness, this hierarchy will further assist clinicians in making evidence-based treatment decisions. Lithium, quetiapine, divalproex, asenapine, aripiprazole, paliperidone, risperidone, and cariprazine alone or in combination are recommended as first-line treatments for acute mania. First-line options for bipolar I depression include quetiapine, lurasidone plus lithium or divalproex, lithium, lamotrigine, lurasidone, or adjunctive lamotrigine. While medications that have been shown to be effective for the acute phase should generally be continued for the maintenance phase in bipolar I disorder, there are some exceptions (such as with antidepressants); and available data suggest that lithium, quetiapine, divalproex, lamotrigine, asenapine, and aripiprazole monotherapy or combination treatments should be considered first-line for those initiating or switching treatment during the maintenance phase. In addition to addressing issues in bipolar I disorder, these guidelines also provide an overview of, and recommendations for, clinical management of bipolar II disorder, as well as advice on specific populations, such as women at various stages of the reproductive cycle, children and adolescents, and older adults. There are also discussions on the impact of specific psychiatric and medical comorbidities such as substance use, anxiety, and metabolic disorders. Finally, an overview of issues related to safety and monitoring is provided. The CANMAT and ISBD groups hope that these guidelines become a valuable tool for practitioners across the globe.

Management of adverse effects of mood stabilizers

Mood stabilizers such as lithium and anticonvulsants are still standard-of-care for the acute and long-term treatment of bipolar disorder (BD). This systematic review aimed to assess the prevalence of their adverse effects (AEs) and to provide recommendations on their clinical management. We performed a systematic research for studies reporting the prevalence of AEs with lithium, valproate, lamotrigine, and carbamazepine/oxcarbazepine. Management recommendations were then developed. Mood stabilizers have different tolerability profiles and are eventually associated to cognitive, dermatological, endocrine, gastrointestinal, immunological, metabolic, nephrogenic, neurologic, sexual, and teratogenic AEs. Most of those can be transient or dose-related and can be managed by optimizing drug doses to the lowest effective dose. Some rare AEs can be serious and potentially lethal, and require abrupt discontinuation of medication. Integrated medical attention is warranted for complex somatic AEs. Functional remediation and psychoeducation may help to promote awareness on BD and better medication management.

Lithium and psoriasis: what primary care and family physicians should know

OBJECTIVE

This review focuses on the association of lithium treatment and psoriasis. The mechanism of action of lithium in causing psoriasis and the clinical presentation of psoriasis secondary to lithium treatment are considered.

DATA SOURCES

A search of the literature from 1949 to 2007 was performed using MEDLINE, with the following search terms: lithium, psoriasis, skin, dermatology, and psychodermatology.

DATA SYNTHESIS

Lithium is involved in a variety of cutaneous reactions including psoriasis, which may present as exacerbation of preexisting psoriasis, induction of de novo psoriasis, pustular psoriasis, nail changes, and psoriatic arthropathy. The appearance of psoriatic lesions may occur at normal therapeutic serum lithium levels. The refractory period for the development of psoriatic lesions is variable and generally longer in induction and shorter in exacerbation of psoriasis. Lithium-induced psoriasis is often resistant to conventional treatment modalities, and some cases may require dose reduction or discontinuation of lithium treatment.

CONCLUSION

Lithium is the mainstay of treatment in bipolar disorder and is associated with a variety of cutaneous side effects including psoriasis. Primary care providers and family physicians should be knowledgeable about the association of lithium and its dermatologic side effects. Early recognition and management could be beneficial in avoiding the issues of noncompliance and further deterioration of mood symptoms secondary to obviously disfiguring skin appearance. Primary care, psychiatry, and dermatology liaison services will prove helpful in managing these patients.

Drug-induced acneiform eruption

Drug-induced acne is a specific subset of acne that usually has some specific features, namely a monomorphic pattern, an unusual location of the lesions beyond the seborrheic areas, an unusual age of onset, a resistance to conventional acne therapy and, of course, the notion of a recent drug introduction. Many drugs can be responsible for such a clinical pattern. Corticosteroids, neuropsychotherapeutic drugs, antituberculosis drugs, and immunomodulating molecules are the more classical drugs associated with induced acne. Recently, new drugs, mainly targeted therapy in the field of oncology, such as epidermal growth factor receptor inhibitors, have been associated with an increased frequency of this adverse effect. Disruption of the culprit drug is rarely mandatory in cases of drug-induced acne. Close cooperation between the dermatologist and medical staff in charge of the patient is an important challenge to achieve optimal management of the initial disease.

Exacerbation of Darier disease by lithium carbonate

INTRODUCTION

Darier disease (DD) and Hailey-Hailey disease (HHD) are rare autosomal dominantly inherited genodermatoses with mutations in the respective genes, ATP2A2 and ATP2C1, that encode the respective calcium adenosine triphosphatases SERCA2 and PMRI/SPCA1. Lithium is an effective therapy used in psychiatry as prophylaxis against recurrent mania and to treat acute schizoaffective, impulsive, and alcoholic disorders.

METHODS

We discuss a patient with DD who claimed that her skin condition had flared after she was administered lithium therapy for bipolar disorder.

DISCUSSION AND CONCLUSIONS

DD may flare after lithium therapy, an association that has rarely been reported. Not uncommonly, DD has been observed to coexist with affective disorders, with reports of the bipolar disorder susceptibility locus cosegregating with a separate DD gene. A mechanism by which lithium worsens disease has recently been studied in rats. DD's coexistence with affective disorders and the mechanisms by which lithium may cause exacerbation of DD and HHD are reviewed.

Acne and systemic disease

Acne is the most common disease of the skin. It affects 85% of teenagers, 42.5% of men, and 50.9% of women between the ages of 20 and 30 years.96,97 The role of hormones, particularly as a trigger of sebum production and sebaceous growth and differentiation, is well known. Excess production of hormones, specifically androgens, GH, IGF-1, insulin, CRH, and glucocorticoids, is associated with increased rates of acne development. Acne may be a feature in many endocrine disorders, including polycystic ovary disease, Cushing syndrome, CAH, androgen-secreting tumors, and acromegaly. Other nonendocrine diseases associated with acne include Apert syndrome, SAPHO syndrome, Behçet syndrome and PAPA syndrome. Acne medicamentosa is the development of acne vulgaris or an acneiform eruption with the use of certain medications. These medications include testosterone, progesterone,steroids, lithium, phenytoin, isoniazid, vitamins B2, B6, and B12, halogens, and epidermal growth factor inhibitors. Management of acne medicamentosa includes standard acne therapy. Discontinuation of the offending drug may be necessary in recalcitrant cases. Basic therapeutic interventions for acne include topical therapy, systemic antibiotics,hormonal agents, isotretinoin, and physical treatments. Generally, the severity of acne lesions determines the type of acne regimen necessary. The emergence of drug-resistant P acnes and adverse side effects are current limitations to effective acne management.

Lithium, antipsychotics, and risk of psoriasis

BACKGROUND

Observations in controlled trials and case reports have linked lithium exposure to induction or exacerbation of psoriasis. A causal relationship between lithium exposure and incident psoriasis has been questioned, and observational studies are lacking.

METHODS

We conducted a case-control analysis using the United Kingdom-based General Practice Research Database to study the association between the use of lithium or antipsychotics and the risk of developing an incident diagnosis of psoriasis. We identified cases with an incident diagnosis of psoriasis between 1994 and 2005, and controls were matched to the cases on age, sex, general practice, calendar time, and years of history in the database. We used conditional logistic regression to estimate the risk of developing a first-time diagnosis of psoriasis in relation to previous exposure to lithium and antipsychotic drugs, stratified by exposure timing and duration. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) adjusted for smoking, body mass index, and additional potential confounders.

RESULTS

We identified 36,702 incident cases of psoriasis and the same number of matched controls. Compared with nonuse, current use of 5 or more prescriptions for lithium and atypical antipsychotics yielded adjusted ORs of 1.68 (95% CI, 1.18-2.39; P < 0.01) and 0.76 (95% CI, 0.55-1.06; P = 0.11), respectively. The OR for olanzapine was 0.50 (95% CI, 0.28-0.89, P = 0.02).

CONCLUSIONS

Long-term use of lithium was associated with a small increase in risk of incident psoriasis. There was a suggestion of a possible reduced psoriasis risk associated with the use of atypical antipsychotics, mainly olanzapine, a finding that needs further evaluation.

Drug-Induced Psoriasis: An Evidence-Based Overview and the Introduction of Psoriatic Drug Eruption Probability Score

Psoriasis is a common skin disorder that needs a long-term management, not only because, of its prevalence but also because of the profound impact it can have on patients quality of life. Drugs may result in exacerbation of a preexisting psoriasis, in induction of psoriatic lesions on clinically uninvolved skin in patients with psoriasis, or in precipitation of the disease in persons without family history of psoriasis or in predisposed individuals. The knowledge of the drugs that may induce, trigger, or exacerbate the disease is of primary importance in clinical practice. By reviewing the literature, there are many reports on drug-induced psoriasis, but the data are not univocal. We propose, when possible, the use of a probability score from the authors to obtain a better classification and further understanding of drug-induced psoriasis.

Anti-inflammatory effects of lithium gluconate on keratinocytes: a possible explanation for efficiency in seborrhoeic dermatitis

Topical lithium (Li) gluconate has a beneficial effect on seborrhoeic dermatitis (SD), unlike oral lithium (Li) used in psychiatry. SD is an inflammatory dermatitis associated, in most of cases, with colonization by lipophilic yeasts of the genus Malassezia. However, the exact mechanism of action of Li gluconate in SD still remains unknown. The aim of our study was to investigate the effect of topical Li on cytokine secretion and innate immunity. For this purpose, we investigated first the modulatory effect of Li on two pro-inflammatory and two anti-inflammatory cytokine secretion and second, the modulatory effect of Li on Toll-like receptor (TLR) 2 and 4 expression by unstimulated and stimulated keratinocytes. Two different skin models were used: keratinocytes in monolayer and skin explants. In some of them, inflammation was induced with LPS (1 mug/ml) or zymosan (2 mg/ml). Then the skin models were incubated with Li gluconate (Labcatal*, Montrouge, France) at three different concentrations (1.6, 3, 5 mM) determined according to viability MTT test. Expression of TNFalpha, IL6, IL10, TGFbeta1, TLR2 and TLR4 was detected by immunohistochemistry (IHC). Cytokines were quantified by ELISA methods. Our results showed that the effect of Li on keratinocytes is dose-dependent. At low concentration (1.6 mM), Li enhanced TNFalpha secretion, whereas, at higher concentration (5 mM), Li significantly enhanced IL10 expression and secretion. However, there was no significant modulation of Li on IL6 and TGFbeta1 secretion. Moreover, Li at 5 mM significantly decreased TLR2 and TLR4 expressions by differentiated keratinocytes. As Li concentration during topical treatment is probably closer to 5 mM than to 1 mM, the therapeutic effect of Li gluconate in DS may be explained by two anti-inflammatory actions: an increased expression and secretion of IL10 and a decreased expression of TLR2 and TLR4 by keratinocytes. The diminution of TLR2 expression by Li may not allow MF to trigger inflammation response in lesional skin.

Triggering psoriasis: the role of infections and medications

Psoriasis can be provoked or exacerbated by a variety of different environmental factors, particularly infections and drugs. Strong evidence exists for the induction of guttate psoriasis by a preceding tonsillar Streptococcus pyogenes infection, whereas disease exacerbation has been linked with skin and/or gut colonization by Staphylococcus aureus, Malassezia, and Candida albicans. The role, if any, of viruses (papillomaviruses, HIV, and endogenous retroviruses) present in lesional skin is at present unknown. The use of various drugs, such as lithium, beta-blockers, antimalarial agents, nonsteroidal anti-inflammatory drugs, and angiotensin-converting enzyme inhibitors, has also been associated with induction or worsening of disease in psoriatic patients.

Lithium suppresses epidermal SERCA2 and PMR1 levels in the rat

Autosomal dominant mutations in the genes encoding the calcium ATPases SERCA2 and PMRI/SPCA1 cause the genodermatoses Darier disease (DD) and Hailey-Hailey disease (HHD), respectively. Recent observations indicated that the level of the pathogenic proteins greatly decreases in the affected areas of the epidermis in these disorders. Here we addressed how lithium, a recognized exacerbating factor in Darier disease, affects the epidermal expression of SERCA2 and PMR1/SPCA1 in the rat as a model. Standard histologic and immunohistochemical methods were utilized in 3 lithium-treated and 3 control animals. A significant suppression of epidermal SERCA2 and PMR1 levels were observed as a result of lithium therapy in addition to marked qualitative and quantitative changes in the stratum corneum and the granular layer of the epidermis in the treated animals. Our findings suggest that exacerbating factors in calcium ATPase disorders of the skin suppress epidermal SERCA2 and PMR1 levels, further decreasing the already haploinsufficient protein expression to a potentially critical level in Darier disease and Hailey-Hailey disease, respectively. Lithium therapy should specifically be avoided not only in Darier disease, but Hailey-Hailey disease as well.