Oral mucosal pigmentation secondary to minocycline therapy: report of two cases and a review of the literature

Severe Discoloration of the Alveolar Bone Secondary to Long-Term Minocycline Therapy: A Case Report

Minocycline, the synthetic derivative of the antibiotic tetracycline, has been used for a variety of medical treatments. One such use for minocycline is for acne vulgaris. Although widely used, minocycline has a common side effect of discoloration of tissues, including bone, skin, and mucosa. This case report presents a 19-year-old female patient with a history of long-term minocycline therapy for acne vulgaris who presented for periodontal esthetic crown lengthening. The initial exam revealed a blue-gray discoloration of the mucosa. Upon surgical exploration, it was discovered that the discoloration originated from the underlying alveolar bone with minimal gingival involvement. Surgical removal and recontouring of the bony exostoses revealed that the bone remained deeply stained. Although the discolored bone was not fully removed, the patient was able to obtain an acceptable esthetic result.

Citalopram-Induced Oral Melanotic Macules in a Female Patient and a Review of the Literature

Pigmented lesions in the oral cavity can arise from the accumulation of external substances or internal pigments, resulting in black or brown discoloration. The etiology can be categorized as physiologic, reactive, neoplastic, idiopathic, or indicative of systemic illness. Several systemic drugs have been linked to the development of oral and/or cutaneous pigmentation, either by stimulating the production of melanin or by the accumulation of the drug or its byproducts. The medications most commonly associated with this condition include antimalarials, hormones, oral contraceptives, phenothiazines, chemotherapeutics, amiodarone, minocycline, zidovudine, clofazimine, and ketoconazole. The aim of this case report is to illustrate the drug-induced appearance of multiple melanotic macules in an 89-year-old female patient. The patient was referred to the Department of Oral Medicine and Pathology, School of Dentistry, Aristotle University of Thessaloniki, Greece, complaining of the recent and constant appearance of black spots in her oral cavity. Her medical history revealed a multitude of prescribed drugs, with citalopram being the most recently prescribed one, approximately one year prior to the examination. The clinical examination revealed multiple melanotic macules, on the upper and lower lip as well as on the hard and soft palate. Based on these findings, a biopsy of a melanotic macule of the lip was carried out. The histopathological examination showed that the basal layer of the stratified squamous epithelium exhibited hyperpigmentation (melanin-pigmented basal cells). In addition, scattered melaninophages were noted in lamina propria. Psychotropic drugs associated with cutaneous hyperpigmentation include citalopram. Therefore, our case constitutes an exception since citalopram induced intraoral and perioral, instead of cutaneous, hyperpigmentation.

Oral hyperpigmentation as an initial clinical aspect of hand foot syndrome

Hand-foot syndrome (HFS) is a common adverse effect of anticancer therapy. It is known to cause dermatological symptoms including acral erythema and dysesthesia of the palms and soles of the feet, swelling, pain, itching, and scaling. Some drugs, like capecitabine, are known to trigger this condition. However, pigmentation of the oral mucosa is a rare adverse effect. This study aims to report a case of oral mucosa hyperpigmentation caused by capecitabine therapy before the clinical diagnosis of HFS. A 58-year-old female, diagnosed with invasive breast duct carcinoma, had the central nervous system, liver, skin, and lung metastasis, using capecitabine every day for 14 cycles. Oral examination revealed multifocal black macules on the hard palate, bilateral buccal mucosa, gingival mucosa, and dorsum of the tongue. The clinical hypothesis was oral mucosa hyperpigmentation by capecitabine use and only periodic follow-up was necessary. Hyperpigmentation of oral mucosa by capecitabine is a rare consequence of neoplastic therapy and your association with HFS is unclear, and poorly reported. The report of these events is important to alert oncology health teams about the individual tolerance to capecitabine therapy.

Tetracyclines and bone: Unclear actions with potentially lasting effects

Tetracyclines are a broad-spectrum class of antibiotics that have unclear actions with potentially lasting effects on bone metabolism. Initially isolated from Streptomyces, tetracycline proved to be an effective treatment for Gram +/- infections. The emergence of resistant bacterial strains commanded the development of later generation agents, including minocycline, doxycycline, tigecycline, sarecycline, omadacycline, and eravacycline. In 1957, it was realized that tetracyclines act as bone fluorochrome labels due to their high affinity for the bone mineral matrix. Over the course of the next decade, researchers discerned that these compounds are retained in the bone matrix at high levels after the termination of antibiotic therapy. Studies during this period provided evidence that tetracyclines could disrupt prenatal and early postnatal skeletal development. Currently, tetracyclines are most commonly prescribed as a long-term systemic therapy for the treatment of acne in healthy adolescents and young adults. Surprisingly, the impact of tetracyclines on physiologic bone modeling/remodeling is largely unknown. This article provides an overview of the pharmacology of tetracycline drugs, summarizes current knowledge about the impact of these agents on skeletal development and homeostasis, and reviews prior work targeting tetracyclines' effects on bone cell physiology. The need for future research to elucidate unclear effects of tetracyclines on the skeleton is addressed, including drug retention/release mechanisms from the bone matrix, signaling mechanisms at bone cells, the impact of newer third generation tetracycline antibiotics, and the role of the gut-bone axis.

Medication-Induced Oral Hyperpigmentation: A Systematic Review

BACKGROUND

Medication-induced oral hyperpigmentation is an oral condition that impacts patients' quality of life and has been linked to many systemic therapeutic agents. The exact pathogenesis of tissue pigmentation varies greatly and is not completely known. This systematic review aimed to present data on the causal association between medications and the development of oral/mucosal pigmentation as an adverse drug reaction.

METHODS

A systematic review and analysis of literature were conducted using the following databases: PubMed, Science Direct, ProQuest, Web of Science, and Scopus. The systematic review included original articles written in English and published between January 1982 and June 2020. Following the PRISMA statement, eligible articles were systematically reviewed, and data were extracted from eligible studies and analyzed.

RESULTS

A total of 235 articles were identified, of which 57 met the inclusion criteria and were included in this review. The mean age of included patients was 46.2±16.38 years (range: 10-90 years) with a male to female ratio of 1:1.45. Oral mucosal hyperpigmentation was reported following the use of several classes of medications such as antiviral (eg, zidovudine), antibiotic (eg, minocycline), antimalarial (eg, chloroquine), anti-fungal (eg, ketoconazole), antileprotic (eg, clofazimine), antihypertensive (eg, amlodipine), chemotherapeutic, and antineoplastic drugs. The risk of developing oral pigmentation was significantly higher with antimalarial medications, antibiotics, antineoplastic and chemotherapeutic agents. Medication-induced oral hyperpigmentation was most frequent among women and in the hard palate.

CONCLUSION

Future research is warranted to better understand the pathogenesis and risk factors for medication-induced oral hyperpigmentation in order to reassure patients during prescription and management.

Oral manifestations related to malaria: A systematic review

OBJECTIVE

To generalize the oral manifestations related to malaria and discuss their clinical significance for health professionals.

MATERIALS AND METHODS

The bibliographic databases of Public MEDLINE, Embase, Web of Science and Scopus were employed to retrieve publications online from January 1781 to August 2019. Original research articles, clinical trials, and case reports published in English were included.

RESULTS

A small number of studies reported oral manifestations of malaria (n = 29), including gingival bleeding, glossitis, oral ulcer, abnormal oral pigmentation, pericoronitis, herpes labialis, herpes gingivostomatitis, bitter taste, sore throat, Burkitt lymphoma of the jaw, alveolar bone resorption, and enamel hypoplasia.

CONCLUSION

Oral manifestations may be important indicators for identification of malaria. Dental and general professionals should pay more attention to oral manifestations in malaria cases, and guide them for specialized examination, diagnosis, and management.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

Black and Brown: Non-neoplastic Pigmentation of the Oral Mucosa

Black and brown pigmentation of the oral mucosa can occur due to a multitude of non-neoplastic causes. Endogenous or exogenous pigments may be responsible for oral discoloration which can range from innocuous to life-threatening in nature. Physiologic, reactive, and idiopathic melanin production seen in smoker's melanosis, drug-related discolorations, melanotic macule, melanoacanthoma and systemic diseases are presented. Exogenous sources of pigmentation such as amalgam tattoo and black hairy tongue are also discussed. Determining the significance of mucosal pigmented lesions may represent a diagnostic challenge for clinicians. Biopsy is indicated whenever the source of pigmentation cannot be definitively identified based on the clinical presentation.

Black pigmentation of both forearm bones after chronic minocycline antibiotic therapy for septic nonunion. A case report and literature review

We report the case of a 28-year-old man with a septic forearm non-union treated with minocycline for 3 months. At the time of reconstructive surgery, the radius and ulna were entirely black. Surgical debridement until bleeding of both bone extremities resulted in a 5-cm defect that was filled with a cement spacer. Histology confirmed poorly vascularized bone with focal areas of acute inflammatory infiltrate at the non-union sites (highly suggestive of infection) and normal structure of the remaining diaphyseal bones, although black in color. Reconstruction with free vascularized fibula transfer was successful leading to complete bone healing. An incidental finding of minocycline-induced black bone discoloration should not change the surgeon's decision because there is no evidence of adverse effects on bone healing in the literature. Surgery can be performed safely at sites of minocycline-induced black bone pigmentation.

Tetracycline@silver ions-functionalized mesoporous silica for high bactericidal activity at ultra-low concentration

Aim: Polyether pores were designed and tetracycline-loaded mesoporous silica materials, with their surface decorated by silver ions, were prepared, with the aim of reaching high antibacterial activity. Meanwhile, mammalian cell cytotoxicity and hemolytic effects were not observed using material concentrations tenfold the ones optimized for the bactericidal tests. Methods: Pore size was tuned by changing the polyether content and the surface was covalently decorated with silver thiolate groups. Results: We showed that the biological activity was enhanced by modulating silver ions and tetracycline releases by tuning silver thiolate group concentration on the silica surface and/or by modulating the pH of the environment. Conclusion: The combined use of tetracycline and silver ions with the mesoporous drug-delivery carrier was a very effective strategy against susceptible and tetracycline-resistant Escherichia coli bacteria.

Physiological oral melanin pigmentation in a South African sample: A clinical study

AIM

Physiological oral melanin pigmentation is genetically determined, more frequently affecting people with darker skin. It can involve any oral mucosal site, but predominantly the gingiva. The aim of the present study was to determine the prevalence and to characterize the clinical features of physiological oral melanin pigmentation in a South African population sample.

METHODS

A trainee in the discipline of periodontology and oral medicine interviewed all participants and examined the oral soft tissues. The diagnosis of physiological oral melanin pigmentation was based on clinical findings and on the history reported by the patient. A predetermined list of exclusion criteria was applied.

RESULTS

The study population comprised 430 participants, of whom 319 (74%) were black, 55 (13%) Indian, 54 (12.5%) white, and two (0.5%) were mixed race. A total of 182 participants were diagnosed with physiological oral melanin pigmentation. The overall prevalence of physiological oral melanin pigmentation in the ethnically-mixed study population was 42%: 54% of blacks were affected, 16% of Indians, and 21% of whites. The female (101): male (81) ratio was 1.2:1; the gingiva was the site most frequently affected (73%). The total number of oral mucosal sites with physiological oral melanin pigmentation in the study population was 263; 68% of participants had one, 22% had two, 7% had three, and 3% had four sites affected. There was no significant association between the number of sites affected and sex or age.

CONCLUSIONS

In this study of a South African population sample, the prevalence of physiological oral melanin pigmentation was higher in blacks than in Indians or whites, and the gingiva was the oral mucosal site most frequently affected.

Case Study: An intraoperative finding of black bone disease in a podiatric surgery patient

Black bone disease has been recognised as a potential consequence of long-term treatment with tetracycline antibiotics. Largely documented affecting structures in the head and skull, there are few reported cases of black bone disease in the foot and ankle. The case of a 55 years old patient, who as a teenager, had undergone treatment with minocycline hydrochloride for chronic acne, and was found to have bone discolouration consistent with minocycline induced black bone disease (MIBBD) during the course of hallux valgus corrective surgery some 40 years later, is presented. In spite of the intraoperative findings, the patient's post-operative recovery and bone healing was uneventful. The literature on minocycline induced black bone disease is reviewed.

A case report: retigabine induced oral mucosal dyspigmentation of the hard palate

Background

Dyspigmentation of the oral mucosa has a multitude of aetiological causes. Retigabine, a new antiepileptic drug, has the potential side effect of inducing a blue/purple pigmentation of the oral mucosa in addition to the skin, lips, nails and retina of the eyes. This article presents a unique case of dyspigmentation present in the oral mucosa of the hard palate which has previously been unreported in the dental literature.

Case presentation

A 70 year old white male presented to a secondary care oral surgery department with an unusual asymptomatic pigmented lesion present in the hard palate of the oral cavity. The pigmentation was remarkable for its distinct blue/purple colouration which was associated with a similar discolouration of the nail beds of the hands. This is believed to be a side effect of the anti-epileptic medication retigabine.

Conclusion

The dental profession and wider healthcare community should be made fully aware of the potential side effect of oral dyspigmentation associated with the novel anti-epileptic medication retigabine. Enhanced knowledge of the causative role of retigabine in dyspigementation of the oral mucosa will allow the practitioner to make an appropriate diagnosis. As far the authors are aware this is reaction is unreported in the dental literature and should be disseminated to the wider oral health professional’s community.

Rusty green stained temporal bone associated with exposure to tetracycline: an unusual presentation of black bone disease

OBJECTIVE

To review the phenomenon and implications of temporal bone and craniofacial bone staining in the context of prolonged exposure to tetracycline antibiotic.

METHODS

Case report and literature review.

RESULTS

A 52-year-old male with a 5-year history of tetracycline use presented to undergo tympanomastoidectomy and was found to have an unusual rusty green pigmentation of the entire aspect of the exposed temporal bone. A literature review revealed more than 20 cases of tetracycline-induced pigmentation of intraoral maxillary and mandibular bone, and 2 prior cases involving the cranial bones.

CONCLUSION

Tissue and organ pigmentation is an unexpected and unfavourable consequence of the use of tetracyclines, particularly minocycline. Tetracycline is contraindicated in children because of the risk for dysosteogenesis and enamel hypoplasia. In adults, although the unusual staining may present as an unexpected dilemma upon surgical exposure, current research shows no significant clinical consequences for this type of pigmentation.

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.

Treatment of acne in children

Acne is a common skin condition in adolescents. It is not uncommon in childhood and it persists into adulthood. A broad range of acne treatments are available and have been shown to be safe and effective in adolescents and adults. However, there is limited literature regarding acne treatment in childhood and its available therapeutic options. It seems reasonable to extrapolate findings of the various studies reported on treatment of acne in the adolescent and adult age group, with the exclusion of the use of tetracycline derivatives. As clinicians, we must be more familiar with the clinical presentation of acne and available treatment options in our younger patients. Early recognition of acne with prompt and appropriate initiation of therapy in childhood will help prevent severe scarring in children.

Evidence-based recommendations for the diagnosis and treatment of pediatric acne

INTRODUCTION

Acne vulgaris is one of the most common skin conditions in children and adolescents. The presentation, differential diagnosis, and association of acne with systemic pathology differs by age of presentation. Current acknowledged guidelines for the diagnosis and management of pediatric acne are lacking, and there are variations in management across the spectrum of primary and specialty care. The American Acne and Rosacea Society convened a panel of pediatric dermatologists, pediatricians, and dermatologists with expertise in acne to develop recommendations for the management of pediatric acne and evidence-based treatment algorithms.

METHODS

Ten major topic areas in the diagnosis and treatment of pediatric acne were identified. A thorough literature search was performed and articles identified, reviewed, and assessed for evidence grading. Each topic area was assigned to 2 expert reviewers who developed and presented summaries and recommendations for critique and editing. Furthermore, the Strength of Recommendation Taxonomy, including ratings for the strength of recommendation for a body of evidence, was used throughout for the consensus recommendations for the evaluation and management of pediatric acne. Practical evidence-based treatment algorithms also were developed.

RESULTS

Recommendations were put forth regarding the classification, diagnosis, evaluation, and management of pediatric acne, based on age and pubertal status. Treatment considerations include the use of over-the-counter products, topical benzoyl peroxide, topical retinoids, topical antibiotics, oral antibiotics, hormonal therapy, and isotretinoin. Simplified treatment algorithms and recommendations are presented in detail for adolescent, preadolescent, infantile, and neonatal acne. Other considerations, including psychosocial effects of acne, adherence to treatment regimens, and the role of diet and acne, also are discussed.

CONCLUSIONS

These expert recommendations by the American Acne and Rosacea Society as reviewed and endorsed by the American Academy of Pediatrics constitute the first detailed, evidence-based clinical guidelines for the management of pediatric acne including issues of special concern when treating pediatric patients.

Minocycline-associated rimmed vacuolar myopathy in a patient with rheumatoid arthritis

BACKGROUND

The autophagic vacuolar myopathies (AVM) are a group of inherited myopathies defined by the presence of autophagic vacuoles in pathological muscle specimens. AVM can be categorized into three groups: acid maltase deficiency, myopathies characterized by autophagic vacuoles with unique sarcolemmal features, and rimmed vacuolar myopathies (RVM). While the pathogeneses of these conditions are still being elucidated, some drugs (e.g., chloroquine, its analog, hydroxychloroquine, and colchicine) can also cause AVM. Minocycline is a disease-modifying anti-rheumatic drug that may be used in the treatment of rheumatoid arthritis (RA). Here, we describe the first case of minocycline-associated AVM with rimmed vacuole formation.

CASE PRESENTATION

A 75-year-old woman suffering from RA has been continuously treated with minocycline (200 mg/day) for the past 7 years. During this time, she developed a myopathy that predominantly affected her lower limbs. Histological studies of biopsied muscle revealed scattered atrophic myofibers with rimmed vacuoles that contained pigment granules. Histochemical staining revealed that the pigment comprised both iron and melanin, which is consistent with type II minocycline-induced cutaneous pigmentation. Under electron microscopy, autophagic vacuoles were consistently observed in association with numerous collections of pigment granules.

CONCLUSIONS

This is the first report of minocycline-induced pigmentation in skeletal muscle. The strong association between autophagic vacuoles and the accumulation of minocycline-induced pigments suggest that long-term minocycline treatment induced pigment accumulation, leading to elevation of autophagic activity and RVM. It might also be possible that minocycline directly activated autophagy, as the observed pigments are known to form complexes containing minocycline and/or its metabolites. As long-term minocycline treatment is expected to be used more widely in the future, we must draw attention to this adverse effect.

Minocycline-induced periarticular black bones in inflamed joints which underwent arthroplastic reconstruction

Background

Minocycline-induced pigmentation of bone (black bone) is well described in tooth-bearing intra-oral bone, but is less known in periarticular bone in patients who have undergone total joint arthroplasty. On a retrospective basis, we investigated the short-term clinico-radiological results of total joint arthroplasties in which the patient developed minocycline-induced periarticular black bone.

Methods

We found 5 cases (0.08%), in 4 patients, of periarticular bone pigmentation revealed during total joint arthroplasties (2 hips, 2 knees, and 1 ankle) in our series of total joint surgeries (6,548 cases) over a 10-year time period in our 3 institutes. Their mean age was 56 years at surgery. All patients had received long-term minocycline treatment. Mean dosage and duration of minocycline was 160 mg/day and 2.2 years, respectively. Minocycline had been prescribed for reactive arthritis (one), rheumatoid arthritis (two) and late infection after total joint arthroplasty (two patients). Mean follow-up period was 3.4 years after the surgeries.

Results

All cases had black or brown pigmentation in the periarticular bones during the surgery. There was no pigmentation in the cartilage or soft tissues of the joints. The mean Japanese Orthopaedic Association (JOA) score or Japanese Society for Surgery of the Foot (JSSF) scale for rheumatoid arthritis foot and ankle joints at latest follow-up (case 1, 66; case 2, 87; case 3, 77; case 4, 77; case 5, 80) improved compared to those of pre-surgery (case 1, 47; case 2, 45; case 3, 55; case 4, 34; case 5, 55). No implant loosening was noted on radiographic examination during the follow-up period. No abnormal bone formation, bone necrosis, hemosiderin deposition, malignancy or metallic debris was found on histological examination.

Conclusions

No clinico-radiological symptoms of total joint arthroplasties showed in the patients with minocycline-induced periariticular black bone in the short-term. Systemic minocycline treatment has the potential to induce significant black pigmentation of many tissues. In particular, minocycline-induced pigmentation of periarticular bone may be accelerated by inflammation due to rheumatic or pyogenic arthritis. Surgeons should recognize the risk of bone pigmentation in inflamed joints due to the systemic treatment of minocycline and explore its influence on periarticular bone and total joint arthroplasty in the long-term.

Mucosal pigmentation caused by imatinib: report of three cases

Imatinib mesylate (STI-571, Gleevec(®)), a tyrosine kinase inhibitor, is a first-line medication for treating chronic myeloid leukemia (CML). Clinical studies revealed very good hematological responses without significant side effects. However, imatinib may lead to mucosal pigmentation. Three patients, two males aged 64 and 53 and one female aged 29 presented with a painless, diffuse, grey-blue pigmentation of the mucosa of the hard palate. Both male patients had a history of CML and had been on imatinib for 4 and 10 years, respectively. The female patient had been on imatinib for 4 years for pelvic fibromatosis. Histopathologically, deposition of fine, dark-brown, spherical granules was noted within the connective tissue. There was no inflammation or hemorrhage, and no melanosis or melanocytic hyperplasia in the epithelium. The granules stained positively for both Fontana-Masson and Prussian blue stains. Imatinib-induced pigmentation is similar to that caused by other medications such as minocycline and anti-malarial medications, namely the deposition of a drug metabolite containing melanin and iron.

Mechanism of pigmentation by minocycline in murine B16 melanoma cells

Long-term treatment with minocycline is known to induce pigmentation or discoloration in tissues but how remains unclear. We investigated the mechanism of pigmentation using B16 melanoma cells. First, we confirmed that intracellular melanin levels increased on minocycline treatment. Then, using the reverse transcriptase-polymerase chain reaction (RT-PCR), we found the expression of mRNA of tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2, to also be significantly increased by treatment with minocycline at 5 µg/ml for 72 h. These results suggest that the minocycline-induced stimulation of melanogenesis occurs at the transcriptional level. Western-blotting revealed slight phosphorylation of extracellular signal-regulated kinase (ERK) 30-60 min after the minocycline treatment. The mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor U0126 and the p38 inhibitor SB203580 were used to examine the signaling pathway associated with the mRNA expression of tyrosinase, TRP-1, or TRP-2 when B16 melanoma cells were treated with minocycline. The SB203580 inhibited the mRNA expression of tyrosinase and TRP-1, suggesting the minocycline-induced melanogensis occurred via a p38 signaling pathway.

Minocycline in acne vulgaris: benefits and risks

Minocycline is a semi-synthetic, second-generation tetracycline. It was introduced in 1972 and has both antibacterial and anti-inflammatory properties. Minocycline is used for a variety of infectious diseases and in acne. Even today, new indications beyond the antibacterial indications are being investigated such as its use in neurologic diseases. Formerly, minocycline was thought to have a superior efficacy in the treatment of inflammatory acne, especially with respect to antibacterial-resistant Propionibacterium acnes. A thorough review of the literature, however, shows that minocycline is not more effective in acne than other tetracyclines. Compared with first-generation tetracyclines, minocycline has a better pharmacokinetic profile, and compared with doxycycline it is not phototoxic. However, minocycline has an increased risk of severe adverse effects compared with other tetracyclines. It may induce hypersensitivity reactions affecting the liver, lung, kidneys, or multiple organs (Drug Reaction with Eosinophilia and Systemic Symptoms [DRESS] syndrome) in the first weeks of treatment and, with long-term treatment, may cause autoimmune reactions (systemic lupus erythematosus, autoimmune hepatitis). In addition, CNS symptoms, such as dizziness, are more frequent compared with other tetracyclines. Long-term treatment may induce hyperpigmentation of the skin or other organs. Resistance of P. acnes to minocycline also occurs, dependent on the prescribing behavior. Considering the aspects of efficacy, its adverse effect profile, resistance, price, and alternatives, minocycline is no longer considered the first-line antibacterial in the treatment of acne.

Treatment of Laugier-Hunziker syndrome with the Q-switched alexandrite laser in 22 Chinese patients

Laugier-Hunziker syndrome (LHS), a rare, acquired pigmentary disorder of the lips, oral mucosa, and fingers, is known to be an entirely benign disease with no systemic manifestations. In the past, the pigmentation has been treated efficiently in a few patients with the Q-switched neodymium: yttrium-aluminum-garnet (Nd:YAG) laser and the Q-switched alexandrite laser (QSAL). In order to evaluate the efficacy and safety of QSAL on Chinese patients of LHS, we treated 22 patients with QSAL in the past 5 years. Treatments were delivered on a bimonthly or trimonthly basis until the abnormal pigmentation totally disappeared. Patients were evaluated at each visit for evidence of dyspigmentation, scarring, or other untoward effects from the laser treatment. Our 22 subjects consisted of 18 females and 4 males with a mean age of 42.4 years. After only one session of laser treatment, the clearing on the lips was as follow: 18 (81.8%) excellent, 2 (9.1%) good, 1 (4.5%) fair and 1 (4.5%) poor. Eighteen patients (81.8%) with LHS, who had achieved excellent clearing after only one session of laser treatment, did not receive further treatment. Among the left four patients, three patients (13.6%) achieved complete results after three laser treatments. Only one patient required six sessions to achieve complete clearance. No scarring was noted after any of the treatments. The appearance of pigmentation on mucous membranes in a middle-aged patient without a significant family history for skin disorders should prompt consideration for the possible diagnosis of LHS. Our study has also demonstrated QSAL to be highly effective and safe in the treatment of LHS.

[Black bone disease of the skull and facial bones]

INTRODUCTION

We report the case of a patient with a craniofacial black bone disease. This was discovered accidentally during a coronal approach.

CASE REPORT

A 38-year-old patient was referred to our unit for facial palsy having appeared 10 years before. Rehabilitation of the facial palsy was performed with a lengthening temporal myoplasty and lengthening of the upper eyelid elevator. An unusual black color of the skull was observed at incision of the coronal approach. Subperiostal dissection of skull and malars confirmed the presence of a black bone disease. A postoperative history revealed minocycline intake (200mg per day) during 3 years.

DISCUSSION

This craniofacial black bone disease was caused by minocycline intake. The originality of this case is to see directly the entire craniofacial skeleton black. This abnormal pigmentation may affect various organs or tissues. Bone pigmentation is irreversible unlike that of the mouth mucosa or of the skin. This abnormal pigmentation is usually discovered accidentally.

Primary mucosal melanoma

Primary mucosal melanomas are rare, biologically aggressive neoplasms. The distribution of head and neck, female genital tract, anal/rectal, and urinary tract sites is 55.4%, 18.0%, 23.8%, and 2.8%, respectively. The median age at presentation is the seventh decade, and women are given the diagnosis more frequently than men. Unfortunately, most afflicted individuals harbor micrometastatic disease and experience a course characterized by multiple local recurrences before the clinical development of distant disease. Approximately a third of patients have nodal involvement at presentation, and the overall 5-year survival is only 25%. Despite aggressive surgical resection and a multitude of adjuvant treatments, the prognosis remains grave. Early detection, which is difficult because of the occult anatomic locations in which these tumors occur, allows the best hope for cure.

Corneal staining after treatment with topical tetracycline

PURPOSE

The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline.

METHODS

A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of bacterial sensitivity testing. After 3 weeks of intensive treatment, the donor cornea was stained with a brownish hue, which was ascribed to the tetracycline drops.

RESULTS

One patient with crystalline keratopathy developed corneal staining after intensive treatment with topical tetracycline eye drops. After a year of follow-up, the staining of the cornea had not changed significantly.

CONCLUSION

Hourly topical tetracycline eye drops may induce corneal pigmentation. To our knowledge, this is the first published case report of corneal staining caused by tetracycline eye drops.