Banca de DEFESA: MARIANE SOARES VIEGAS MOURA REZENDE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIANE SOARES VIEGAS MOURA REZENDE
DATE: 27/07/2023
TIME: 14:00
LOCAL: Instituto de Ciências Farmacêuticas
TITLE:

Impact of hypovitaminosis D on the pathophysiology of pityriasis alba in adults

KEY WORDS:

Pityriasis alba. Eczematid. Vitamin D. Serum level. Hypopigmentation. 1,25(OH)Vitamin D. Cell differentiation. Melanogenesis. Melanocytes. Pathophysiol

PAGES: 71
BIG AREA: Ciências da Saúde
AREA: Medicina
SUBÁREA: Clínica Médica
SPECIALTY: Dermatologia
SUMMARY:

Introduction: Pityriasis Alba (PA) is a condition mottled by asymptomatic, hypopigmented, slightly
scaly patches with indistinct margins. The etiology of PA is not well established. Vitamin D exerts
its effect through a nuclear receptor present mainly in cells involved in bone metabolism; These
receptors are also present on other cell types in the skin such as melanocytes, keratinocytes, immune
system cells and fibroblasts. Calcium controls the activity of thioredoxin reductase which is
cytosolic and associated with the plasma membrane. If the level of intracellular calcium decreases,
this leads to reduced high levels of thioredoxin, which, in turn, inhibit tyrosinase activity,
progressively initiated in melanin synthesis. Objective: There are few studies correlating the effect
of hypovitaminosis D with the pathogenesis of AP, therefore, the objective of our study was to
correlate vitamin D with the pathophysiology of AP. Patients and methods: This was a case-
control, open and non-randomized study, where 9 patients over 18 years of age with AP clinically
diagnosed at the Clinical Dermatology outpatient clinics of CER III of PAM Salgadinho in Maceió
were selected, over an estimated period of 6 months. The control group consisted of 9 patients not
affected by AP or any other hypopigmented disorders. Blood samples were collected from both
groups (cases and controls) and circulating serum 25(OH)D levels were measured. Primary variables
analyzed were serum levels of vitamin D, number and size of lesions, degree of depigmentation
and/or presence of erythema, affected region and present symptoms. The secondary variables were
the demographic profile of the patients and the tertiary variables were the habits related to bathing.
Calculations were performed using the BIOESTAT v.5.3 software and the two-sample “T” test. Data
were statistically analyzed using the Mann-Whitney U test, the chi-square test and the Fischer test
for primary, secondary and tertiary variables, respectively. An alpha value equal to or less than 0.05
was used to reject the null hypothesis. Results: The results of the vitamin D assessment among the
cases showed that none of them had a sufficient level of vitamin D and the level varied between
11.1-27.5 ng/ml (mean: 19.666 ± 5.099 ng/ml). Five patients (55.5%) had impairment and four
patients (44.4%) had impairment. In the control group, the level ranged from 11.3 to 44.7 ng/ml
(mean: 31.777 ± 10.195 ng/ml). Only 01 patient in the control group (11.1%) had vitamin D
deficiency, 03 (33.3%) were insufficient and 5 (55.5%) had sufficiency. Comparing the vitamin D
levels of both groups, there was a statistically significant difference (p = 0.0071). In the case group,
3 out of 4 patients with severe hypochromia had deficient levels of vitamin D, 1 of which was
insufficient. Furthermore, of the 6 patients with more than 5 PA lesions, half had vitamin D deficient
and the other half insufficiency levels. The only patient with more than 10 lesions had a deficient
serum level of vitamin D. Conclusions: The association between hypovitaminosis D and the
occurrence and severity of AP in adults is a relevant finding, as it suggests that vitamin D
supplementation may be a therapeutic option for this condition.

BANKING MEMBERS:
Presidente - 1547952 - EURICA ADELIA NOGUEIRA RIBEIRO
Interno(a) - 1974414 - OLAGIDE WAGNER DE CASTRO
Externo(a) ao Programa - 3509820 - MARIA ALINE BARROS FIDELIS DE MOURA