Comparison of the clinical efficacy of NBUVB and NBUVB with benzoyl peroxide/clindamycin in progressive macular hypomelanosis

Post-Inflammatory Hypopigmentation: Review of the Etiology, Clinical Manifestations, and Treatment Options

Post-inflammatory hypopigmentation is a common acquired pigmentary disorder that is more prominent in skin of color, leading to great cosmetic and psychosocial implications. Often, a diagnosis with a pigmentary disorder can negatively impact an individual's health-related quality of life and may result in stigma. Although most cases of post-inflammatory hypopigmentation resolve spontaneously over time, a systematic diagnostic approach can help with identifying the underlying etiology and informing treatment strategies. It can be due to cutaneous inflammation, sequelae of inflammatory or infectious dermatoses, or dermatologic procedures. Therefore, a thorough understanding of the epidemiology, patient history, physical exam findings, and clinical features of post-inflammatory hypopigmentation phenomenon can explain the primary cause to providers and allow for patient education. It is also important to understand the various therapeutic approaches available and the efficacy of these options, which will inform providers to choose the appropriate therapy for patients. Although algorithms exist for classifying acquired disorders of hypopigmentation, there are no established algorithms for the diagnosis and treatment of post-inflammatory hypopigmentation, which warrants further exploration and discourse.

Successful treatment of progressive macular hypomelanosis

Progressive Macular Hypomelanosis (PMH) is a common but often misdiagnosed disorder of acquired hypopigmentation. An adolescent female presented with irregular, hypopigmented patches ultimately diagnosed as PMH. Complete repigmentation was achieved with narrowband UVB phototherapy, benzoyl peroxide wash, and clindamycin lotion.

Is Cutibacterium (previously Propionibacterium) acnes a potential pathogenic factor in the aetiology of the skin disease progressive macular hypomelanosis?

Progressive macular hypomelanosis (PMH) is a skin condition that normally causes symmetrically distributed hypopigmented macules on the front and back of the trunk, but rarely the face. To date, the pathophysiology of the condition is not well understood, but a role for the anaerobic skin bacterium Cutibacterium (previously Propionibacterium) acnes in the development of the disease has been proposed due to its sole presence within lesional, but not normal peri-lesional, skin. The success of antimicrobials in the treatment of PMH also provides circumstantial evidence that this association may be causal, although this is still to be proven. More recent culture and metagenomic typing studies indicate that strains of C. acnes subsp. elongatum (type III) may be important in the aetiology of the condition, which would help to explain why PMH does not normally affect the face since such strains are rarely present there, and why no association between this condition and acne vulgaris is found; acne appears to primarily involve type IA₁ strains from C. acnes subsp. acnes (type I). In this review, we summarize current knowledge on the relationship between C. acnes and PMH, and re-examine previous challenges to the view that the bacterium plays a role in the condition against the backdrop of newly emerged data.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Propionibacterium Acnes Phylogenetic Type III is Associated with Progressive Macular Hypomelanosis

Progressive macular hypomelanosis (PMH) is a skin disorder that is characterized by hypopigmented macules and usually seen in young adults. The skin microbiota, in particular the bacterium Propionibacterium acnes, is suggested to play a role.

Here, we compared the P. acnes population of 24 PMH lesions from eight patients with corresponding nonlesional skin of the patients and matching control samples from eight healthy individuals using an unbiased, culture-independent next-generation sequencing approach. We also compared the P. acnes population before and after treatment with a combination of lymecycline and benzoylperoxide.

We found an association of one subtype of P. acnes, type III, with PMH. This type was predominant in all PMH lesions (73.9% of reads in average) but only detected as a minor proportion in matching control samples of healthy individuals (14.2% of reads in average). Strikingly, successful PMH treatment is able to alter the composition of the P. acnes population by substantially diminishing the proportion of P. acnes type III.

Our study suggests that P. acnes type III may play a role in the formation of PMH. Furthermore, it sheds light on substantial differences in the P. acnes phylotype distribution between the upper and lower back and abdomen in healthy individuals.

Adjuvant Narrow Band UVB Improves the Efficacy of Oral Azithromycin for the Treatment of Moderate to Severe Inflammatory Facial Acne Vulgaris

Background:

Acne vulgaris (AV) is a common inflammatory disease of the pilosebaceous unit. A variety of treatment modalities are available for the treatment of AV. Among the available options, oral azithromycin is popularly prescribed for its proven anti-inflammatory effects. Narrow band UVB (NBUVB) also has a potent anti-inflammatory action. Concomitant use of both modalities may result in a synergistic therapeutic response; however, the combined efficacy has not yet been evaluated for the treatment of inflammatory AV.

Objective:

The aim of this study was to compare the efficacy of oral azithromycin plus NBUVB (peak 311 nm) to oral azithromycin alone for the treatment of moderate to severe inflammatory AV.

Materials and Methods:

A randomized, open-label, clinical trial was conducted over 4 weeks. Subjects were randomized into two groups. Group 1 received 500 mg of oral azithromycin three times per week. Group 2 received 500 mg of oral azithromycin plus NBUVB three and two times per week, respectively. Concomitant topical or oral AV treatments were not permitted during the treatment period. Response to treatment was measured by photographic records at the primary endpoint (2 weeks) and at the end of treatment.

Results:

One hundred and four subjects were enrolled in the trial; 94 subjects completed the treatment period of the study. Group 2 demonstrated significant clinical improvement of the inflammatory papular lesions (88.55%) compared with group 1 (70.34%) at the end of treatment (P = 0.002). The clinical response of pustular (P = 0.562), nodular (P = 0.711) and cystic (P = 0.682) lesions did not significantly differ between the two treatment groups. Interestingly, response to treatment in group 2 had a significant anatomical predilection for the forehead (P = 0.023). There was no side-effect except erythema, which subsided within 1-2 days.

Conclusion:

NBUVB plus oral azithromycin is more effective than oral azithromycin alone for treating papular lesions of inflammatory AV. NBUVB is certainly a viable adjunct in acne therapy.