Minocycline-associated intra-oral soft-tissue pigmentation: clinicopathologic correlations and review

Blue laser-assisted depigmentation of gingiva using non-ablative technique

Diode lasers are one of the most widely used modalities in soft tissue dental surgery. Recent advancements have expanded the clinically useful emission spectrum of diode lasers to include the blue light region, corresponding to wavelengths such as 445 and 450 nm. The melanin present in hyperpigmented gingiva acts as a chromophore and absorbs laser energy, thus facilitating the denaturing of melanin-containing cells in the gingiva. This paper presents a case of ethnicity-related gingival hyperpigmentation that was successfully treated using a 445 nm blue wavelength soft tissue diode laser by non-ablative technique. The treated area showed no recurrence of pigmentation up to 9 months postoperatively.

Explaining the colour of natural healthy gingiva

To examine the differences between natural gingival colour in men and women. To determine the degree of predictability of changes in the gingival colour coordinates recorded for healthy gingiva, according to age, long-term medication, frequency of toothbrushing, and smoking habits. The CIELAB colour coordinates were recorded using a spectrophotometer for 360 Caucasian adult participants (aged 18-92 years), in three zones of the healthy attached gingiva of the maxillary central incisor. Regression models were created for each zone and each sex, taking the L*, a* and b* coordinates as dependent variables and age, frequency of toothbrushing, smoking habits (0-non-smoker; 1-smoker) and whether participants were taking long-term medication (0-no; 1-yes) as independent variables. The statistical analysis was conducted with SPSS version 26.0, using multiple regression models. Statistically significant differences between men and women were found only for colour coordinate b*, in all three zones. The only colour coordinate on which the predictor variables had a significant effect was the L* coordinate. In men, age and long-term medication had the greatest effect as predictors (maximum R2 = 0.149). In women, frequency of toothbrushing was the strongest predictor in the predictive models (maximum R2 = 0.099). The colour of gingiva in men contained a larger amount of blue, given that significantly lower values for colour coordinate b* were recorded in men than women, although this difference lacked clinical implications. For both sexes, the regression models produced had a modest predictive capacity. The L* coordinate was the dependent variable that showed the greatest predictability.

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.

Relationship of Medication Intake and Systemic Conditions with Periodontitis: A Retrospective Study

OBJECTIVES

To examine the potential relationship of medication intake and systemic conditions with periodontitis.

METHODS AND MATERIALS

A total of 1985 patient records with a diagnosis of periodontal health and stage III and IV periodontitis were included in the analysis. Demographic characteristics, the number of missing teeth, patient-reported medical conditions and medication intake as well as smoking habits were recorded. Regression models were performed to explore the outcomes.

RESULTS

Older individuals, Hispanic ethnic groups, Black and Hispanic or Latino racial groups and non-White individuals in general were significantly more frequently diagnosed with periodontitis than health. Hypertension, glaucoma, anxiety and depression were significantly associated with periodontitis, while cancer, alcohol use, kidney problems, asthma, sleep apnea and gastrointestinal disorders were associated with periodontal health. Patients who reported taking anticoagulants, statins and ACE inhibitors demonstrated 3.546 (95% CI: 1.982, 6.343), 2.771 (95% CI: 1.877, 4.09) and 4.847 (95% CI: 2.785, 8.434) times higher odds of having periodontitis, respectively.

CONCLUSION

Within the limitations of this retrospective study that utilized the BigMouth dental data repository, there is a possible relationship between systemic medications including anticoagulants, ACE inhibitors and statins as well as systemic medical conditions including hypertension, glaucoma, anxiety and depression with periodontitis.

Voltage-Gated Proton Channel Hv1 Regulates Neuroinflammation and Dopaminergic Neurodegeneration in Parkinson's Disease Models

Although the precise mechanisms for neurodegeneration in Parkinson's disease (PD) are unknown, evidence suggests that neuroinflammation is a critical factor in the pathogenic process. Here, we sought to determine whether the voltage-gated proton channel, Hv1 (HVCN1), which is expressed in microglia and regulates NADPH oxidase, is associated with dopaminergic neurodegeneration. We utilized data mining to evaluate the mRNA expression of HVCN1 in the brains of PD patients and controls and uncovered increased expression of the gene encoding Hv1, HVCN1, in the brains of PD patients compared to controls, specifically in male PD patients. In an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 × 16 mg/kg) mouse model of PD, Hvcn1 gene expression was increased 2-fold in the striatum. MPTP administration to wild-type (WT) mice resulted in a ~65% loss of tyrosine hydroxylase positive neurons (TH+) in the substantia nigra (SN), while a ~39% loss was observed in Hv1 knockout (KO) mice. Comparable neuroprotective effects of Hv1 deficiency were found in a repeated-dose LPS model. Neuroprotection was associated with decreased pro-inflammatory cytokine levels and pro-oxidant factors in both neurotoxicant animal models. These in vivo results were confirmed in primary microglial cultures, with LPS treatment increasing Hvcn1 mRNA levels and Hv1 KO microglia failing to exhibit the LPS-mediated inflammatory response. Conditioned media from Hv1 KO microglia treated with LPS resulted in an attenuated loss of cultured dopamine neuron cell viability compared to WT microglia. Taken together, these data suggest that Hv1 is upregulated and mediates microglial pro-inflammatory cytokine production in parkinsonian models and therefore represents a novel target for neuroprotection.

Minocycline-Induced Gum Pigmentation during Treatment for Acne Vulgaris

Minocycline, a type of tetracycline, is a broad-spectrum antibiotic that is commonly prescribed in dermatology for the treatment of acne vulgaris. Common side effects of minocycline include nausea, vertigo, and dizziness while less common side effects include hyperpigmentation. In this case study, we found an 18-year-old female who presented with dark blue pigmentation in her upper gum after using minocycline on and off for 4 years. After discontinuation of the minocycline for 2 years, the pigmentation decreased gradually.

Gingival pigmentation: Concurrent assessment of distribution, intensity, and extent in a black population

OBJECTIVE

To evaluate prevalence, distribution, intensity and extent of physiologic gingival melanin pigmentation (GMP) in black individuals.

MATERIALS AND METHODS

For this cross-sectional study, GMP was evaluated on digital images by three calibrated examiners, according to de Krom (distribution), DOPI (intensity) and Melanin Index (extent) classifications. Descriptive statistics, Wilcoxon, Mann-Whitney, Kruskal-Wallis, Two-way ANOVA, chi square, and K-means cluster analysis were used.

RESULTS

Seventy participants were recruited. The most prevalent GMP categories were: de Krom category 2 (34.3%), DOPI heavy intensity (57.2%), and Melanin index Degree IV (50%). Significant inter-group differences were found for age (p < 0.05) but not gender (p > 0.05). Significant correspondence/overlap was observed between classifications (p > 0.05). Three GMP clusters were identified: Cluster 1 (27%; n = 19) had mild asymmetric and interspersed pigmentation; Cluster 2 (46%; n = 32) had heavy pigmentation in one long continuous ribbon, with pink marginal gingiva; and Cluster 3 (27%; n = 19) had heavy pigmentation in one long continuous ribbon, symmetric, and uniform.

CONCLUSIONS

There may be overlap among GMP classification systems. In black individuals, the predominant GMP presentation is one of a broad zone of heavily pigmented attached gingiva, in a continuous strip from central incisors to canines, symmetrical across the midline, and with pink free marginal gingiva.

CLINICAL RELEVANCE

This is the first study to analyze distribution, intensity, and extent of gingival melanin pigmentation in the same population and to integrate the various classification systems through cluster analysis. The novel findings provide a foundation for patient assessment and counseling and for future studies.

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.

Q-switched 532 nm Nd:YAG laser therapy for physiological lip hyperpigmentation: novel classification, efficacy, and safety

BACKGROUND

Physiological lip hyperpigmentation (PLH) is a common cosmetic concern in the Middle East and Asia. It is characterized by homogeneous symmetric diffuse hyperpigmentation affecting both lips. There is no satisfactory treatment for this condition. The aim of this study is to evaluate the efficacy and safety of Q-switched (QS) 532 nm Nd:YAG laser for PLH.

METHODS

A total of 30 patients with clinical diagnosis of PLH were retrospectively reviewed and included in the study. Patients underwent at least one laser treatment using QS 532 nm with a minimum follow up of six months. Laser parameters were as follows: spot size 2-3 mm, pulse duration 20 ns, fluence 2-4 J/cm². One to three sessions were performed depending on clinical response. Two methods were used for assessment: patient satisfaction and independent physician assessment. PLH was classified as grade 1 (upper lip fully affected plus only border of lower lip), grade 2 (upper lip fully affected plus most of lower lip), and grade 3 (majority of both lips hyperpigmented).

RESULTS

Excellent (>75% improvement) response was achieved in 30% of patients. Good (51-75% improvement) response was seen in 37% and 43% of patients according to patient satisfaction and independent physician assessment, respectively. Majority of patients required only one treatment session. Reactivation of herpes labialis occurred in two patients, and mottled hypopigmentation in three patients. None of the patients developed persistent hyperpigmentation or scarring.

CONCLUSIONS

PLH can be effectively treated with QS 532 nm Nd:YAG laser and is well tolerated by patients.

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.

Sensory Processing Phenotypes in Fragile X Syndrome

Fragile X syndrome (FXS) is a neurodevelopmental disorder that causes intellectual disability. It is a leading known genetic cause of autism. In addition to cognitive, social, and communication deficits, humans with FXS demonstrate abnormal sensory processing including sensory hypersensitivity. Sensory hypersensitivity commonly manifests as auditory, tactile, or visual defensiveness or avoidance. Clinical, behavioral, and electrophysiological studies consistently show auditory hypersensitivity, impaired habituation to repeated sounds, and reduced auditory attention in humans with FXS. Children with FXS also exhibit significant visuospatial impairments. Studies in infants and toddlers with FXS have documented impairments in processing texture-defined motion stimuli, temporal flicker, perceiving ordinal numerical sequence, and the ability to maintain the identity of dynamic object information during occlusion. Consistent with the observations in humans with FXS, fragile X mental retardation 1 ( Fmr1) gene knockout (KO) rodent models of FXS also show seizures, abnormal visual-evoked responses, auditory hypersensitivity, and abnormal processing at multiple levels of the auditory system, including altered acoustic startle responses. Among other sensory symptoms, individuals with FXS exhibit tactile defensiveness. Fmr1 KO mice also show impaired encoding of tactile stimulation frequency and larger size of receptive fields in the somatosensory cortex. Since sensory deficits are relatively more tractable from circuit mechanisms and developmental perspectives than more complex social behaviors, the focus of this review is on clinical, functional, and structural studies that outline the auditory, visual, and somatosensory processing deficits in FXS. The similarities in sensory phenotypes between humans with FXS and animal models suggest a likely conservation of basic sensory processing circuits across species and may provide a translational platform to not just develop biomarkers but also to understand underlying mechanisms. We argue that preclinical studies in animal models of FXS can facilitate the ongoing search for new therapeutic approaches in FXS by understanding mechanisms of basic sensory processing circuits and behaviors that are conserved across species.

Mucocutaneous Hyperpigmentation in a Patient With a History of Both Minocycline and Silver Ingestion

Minocycline is a derivative of tetracycline. It has been widely used in dermatology for the treatment of acne and rosacea. One of its adverse effects is pigmentation of various body tissues. Clinically, 3 main distinct types of hyperpigmentation by minocycline have been distinguished: type I, with blue-gray to black pigment on the face in areas of scarring or inflammation; type II, with blue-gray pigment on normal skin of the legs, forearms and on the shins; and type III, with a diffuse muddy-brown discoloration in areas of sun exposure. In the current report, we present the case of a 50-year old man with a history of severe acne treated with minocycline in the past, who currently complained about discoloration of his face. He had also taken colloidal silver supplements for "good health" about 16 years ago. Physical examination revealed gray-blue discoloration on the face, sclera, hard palate and back. Histologic examination showed intracellular pigment deposits in macrophages of the superficial dermis in a perivascular and an interstitial distribution. The pigment stained with Fontana-Masson and von Kossa, whereas it was Perls' iron negative. This case does not fit well into any of the previously described patterns of minocycline-related hyperpigmentation.

[Pigmentations of the oral cavity]

Buccal mucosa color is explained by hemoglobin in the vessels and melanin in the epithelium. Abnormal presence of melanin pigments (hypermelaninosis, hypermelanocytosis), hematic pigments (hemoglobin, hemosiderin, iron) but also some exogenous circonstancies explain pigmented lesions (figure 1). These lesions could be localized (single lesions), multifocal (multiple lesions) or diffused. In case of a localized pigmentation with melanic appearance, melanoma must be systematically eliminated with a biopsy. In the case of a more diffused lesion, systemic disease must be evoked. A drug etiology is also possible. A blood pigment excess could be a vascular malformation (flat lesions) or a tumoral process (nodular or swollen lesions). In both cases, Kaposi's disease should be systematically eliminated. Pigmentations near dental restorations (amalgams, prosthetic crowns) could be explained by an exogenous factor but a biopsy should be performed in case of a doubt with melanoma.

Approaches to the evaluation of lip hyperpigmentation

Hyperpigmentation of the lips is a common condition. It is associated with a wide variety of conditions that include physiologic changes, genodermatoses, inflammatory diseases, endocrinologic disorders, drugs and chemicals, benign and malignant neoplasm, and other non-melanotic conditions. The aim of this article is to provide a clinical approach to hyperpigmented lesions on the lips based on the extent of lesions, the age of onset, and associated systemic involvements. In this review, we present an algorithm to guide the diagnosis of and plan for therapeutic intervention for pigmented lesions of the lips. The algorithm is based on the typical clinical presentation of each entity and should not be taken as an absolute indicator of diagnosis. Although the differences in color can help to differentiate among pigmented lesions, the interpretation of color can be subjective and is influenced by the amount and location of the pigment within the mucosa. The limitations of this review are that some data are based on case reports and small case series that may not reflect true association.

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.

Side effects of minocycline treatment in patients with fragile X syndrome and exploration of outcome measures

Minocycline can rescue the dendritic spine and synaptic structural abnormalities in the fragile X knock-out mouse. This is a review and preliminary survey to document side effects and potential outcome measures for minocycline use in the treatment of individuals with fragile X syndrome. We surveyed 50 patients with fragile X syndrome who received minocycline for at least 2 weeks and found that the most common reported side effect is gastrointestinal difficulty, including loss of appetite. The families reported an improvement in language and behavioral areas. Outcome measures in the design of future randomized clinical trials should include both behavioral and language measures. As with any other treatments, we emphasize that randomized clinical trials are needed to determine the efficacy of minocycline in fragile X syndrome.

Oral melanoacanthoma in an adolescent

The etiopathogenesis of oral pigmentation is diverse. One such process is the oral melanoacanthoma, a reactive, melanocytic lesion, infrequently found in the pediatric subpopulation. To extend the knowledge of this lesion, we provide a case of gingival melanoacanthoma in a 17-year-old male patient. In addition, a comprehensive differential diagnosis for gingival hyperpigmentations in young patients is detailed.

Staining of palatal torus secondary to long term minocycline therapy

Minocycline and other tetracycline analogs are well known to cause discoloring of alveolar bone, teeth and other tissues. The present case reports palatine torus discoloring, in a 91-year-old patient, after long term minocycline therapy. The patient was presented with staining of the palatal torus resulting from prior minocycline use for three-and-a-half years. The diagnosis of minocycline staining of palatal torus was done during a routine hygiene examination. The patient was informed that the bluish appearance of the palatal torus was the result of long term minocycline use. The patient was not willing to discontinue the antibiotic and was not concerned about the appearance. The clinician should inform patients on long term minocycline therapy about the possible side effects of staining of the alveolar bone, teeth and other soft tissue.

Potential Iatrogenic Tetracycline Staining of Endodontically Treated Teeth via NaOCl/MTAD Irrigation: A Preliminary Report

This study reported red-purple staining of light-exposed, root-treated dentin when root canals were rinsed with 1.3% NaOCl as initial rinse followed by the use of BioPure MTAD as final rinse. This intrinsic dentin staining occurred irrespective of whether the root canals were filled, and could be observed even in crown dentin when the latter was sequentially immersed in NaOCl and MTAD. Bench-top reproductions of the phenomenon revealed that the exothermic reaction is not an acid-base reaction. Conversely, the reaction is of a redox nature that highly resembled the previously reported mechanism of tetracycline staining, in which photo-oxidation of tetracycline resulted in a red-purple tetracycline degradation product that has a high affinity for hydroxyapatite. This photo-oxidative degradation process is probably triggered by the use of NaOCl as an oxidizing agent, and may be prevented by rinsing the NaOCl-treated dentin with ascorbic acid, a reducing agent, before the application of MTAD.