Presumed isotretinoin-induced, concomitant autoimmune thyroid disease and ocular myasthenia gravis: a case report

Is routine laboratory testing in healthy young patients taking isotretinoin necessary: a critically appraised topic

CLINICAL QUESTION

Is monitoring of liver function, lipids and full blood count necessary in healthy people taking isotretinoin?

BACKGROUND

Routine blood testing was recommended in the original licence for Roaccutane™ (isotretinoin) in 1983. In recent years, less frequent monitoring has been suggested by various authors.

DATA SOURCES

We performed four individual systematic searches of the MEDLINE database, via PubMed, from origin to 2 May 2021, supplemented by a hand search of all references in the identified papers.

STUDY SELECTION

Inclusion criteria were any description of clinical symptoms, laboratory abnormalities and/or physical findings, and any paper that explicitly described the patients as asymptomatic, during treatment with oral isotretinoin.

DATA EXTRACTION

Two independent reviewers (J.A. and D.J.) assessed articles for eligibility of inclusion. Evaluation of the data was done also by two of the authors (A.A., D.J. and J.A.) for each section, with the aim to use the presented evidence including guidelines, databases, case series, case reports, cohort studies and randomized clinical trials to delineate the clinical presentation and frequency of adverse events that might be amenable to laboratory monitoring.

RESULTS

We identified 407 papers in our searches and reviewed 125 papers in four sections. Overall, reported adverse events were very rare (< 1 in 10 000) and were either idiosyncratic or not preventable by monitoring, accompanied by symptoms, or seen in identifiable predisposed individuals who might benefit from monitoring because of pre-existing conditions.

RECOMMENDATION FOR CLINICAL CARE

We could not find evidence to support the benefit of monitoring to detect adverse events. We suggest that in healthy young people laboratory monitoring for oral isotretinoin is unnecessary and risks detecting nonserious biochemical abnormalities. However, we recognize that new information about adverse events may change that recommendation.

Patterns of thyroid dysfunctions in adolescent patients suffering from severe acne during isotretinoin treatment

Although oral isotretinoin has been widely used as a basic treatment of acne in adolescents, several studies have noted some alterations in thyroid functions during oral isotretinoin therapy. Therefore, the present study aims at evaluating the possible changes in thyroid-stimulating hormone (TSH), free thyroxin (fT4) and free triiodothyronine (fT3) levels during isotretinoin treatment and analyzing the possible factors which may contribute to such changes. In the present study, 47 patients received (0.5 mg/kg oral isotretinoin) for treatment of severe acne. TSH, fT4 and fT3 were measured at baseline, after 3 and 6 months. ANOVA tests were used for statistical analyses. The levels of fT4 and fT3 decreased significantly during isotretinoin treatment (from 0.85 ± 0.04 and 3.1 ± 0.26 at baseline to 0.81 ± 0.023 and 2.76 ± 0.2 after 6 months, respectively). The decrease was accompanied by significant elevation of TSH (0.66 ± 0.05 at baseline to 0.695 ± 0.05 after 6 months). The duration of therapy (but not the dose) has significantly affected all the hormonal changes. Previous incomplete or intermittent isotretinoin treatment had significantly influenced the changes in fT4 only, while gender affected the changes of TSH. Isotretinoin treatment can decrease fT4, fT3 and increase TSH. The pattern of these changes was affected by gender and previous isotretinoin therapy. Different doses of isotretinoin did not affect the hormonal changes, but the duration has been the major influencing factor.

Isotretinoin as a Possible Environmental Trigger to Autoimmunity in Genetically Susceptible Patients

Introduction. Isotretinoin is commonly used to treat cystic acne. Definitive mechanisms of action for isotretinoin are not known though despite many side effects having been documented. Various case reports have noted autoimmune diseases succeeding isotretinoin treatment. Case Report. A 16-year-old female presents with symptoms of tremors, lack of focus, sleeplessness, emotional liability, bulging eyes, loose stools, heat intolerance, and missed menstrual periods. Symptoms manifested shortly after the patient finished a course of oral isotretinoin treatment for acne. Physical exam showed resting tremors, bilateral proptosis, hyperactivity, and rapid speech. A diagnosis of Graves' Disease was made by correlating symptoms, physical exam findings, ultrasound, and positive family history of autoimmune thyroid disease. Conclusion. Emergence of autoimmune thyroid diseases depends upon genetic predisposition and environmental triggers. Mechanism of action for isotretinoin is not known but the drug may play a role in triggering autoimmunity in genetically susceptible individuals.

Side effects of retinoid therapy on the quality of vision

Retinoids are compounds chemically related to vitamin A, which are frequently used in dermatological practice (1). They are characterized by numerous mechanisms of action leading to normalization of keratinocyte proliferation and maturation. They have anti-seborrhoeic, immunomodulatory and anti-inflammatory effects (1, 2). A number of side effects to retinoid treatment have been recorded; one group of such side effects relates to eyes and vision. Dry eye syndrome and blepharoconjunctivitis are the most common side effects, appearing in 20-50 % of patients treated with retinoids. They often contribute to the occurrence of other side-effects such as eye discomfort and contact lens intolerance. Due to the widespread use in clinical practice, the adverse effects, including ocular side effects, should be studied. To confirm the variety of adverse effects of retinoids, several case reports of rare side-effects are presented.

Evaluation of thyroid function tests of acne vulgaris patients treated with systemic isotretinoin

BACKGROUND

Isotretinoin is a systemic retinoid used to treat acne and it binds receptors which are the member of steroid-thyroid hormone superfamily. Certain types of retinoids may cause abnormalities in serum thyroid function tests (sTFTs) by suppressing thyroid stimulating hormone (TSH). However, it is uncertain whether systemic isotretinoin has any effect on sTFTs.

OBJECTIVE

The aim of the study was to find out if there is any alteration in sTFTs of patients with acne vulgaris treated with systemic isotretinoin.

METHODS

A total of 51 patients (male/female: 22/29) with severe acne vulgaris treated with a total dose of 120 mg/kg isotretinoin were included into the study prospectively. Serum free T3 (fT3), free T4 (fT4) and TSH levels were measured at baseline, 3rd and 6th months of treatment.

RESULTS

Mean serum TSH levels at baseline, 3rd and 6th months of treatment were 1.57 ± 0.67, 2.07 ± 0.88 and 2.25 ± 0.86 uIU/mL, respectively. Mean serum TSH levels increased significantly following isotretinoin therapy (p < 0.01, p = 0.007 and p < 0.01, respectively). Mean serum fT3 levels at baseline, 3rd and 6th months of treatment were 3.59 ± 0.57, 3.19 ± 0.45 and 3.09 ± 0.61 pmol/L, respectively. Mean serum fT4 levels at baseline, 3rd and 6th months of treatment were 1.21 ± 0.19, 1.09 ± 0.16 and 1.11 ± 0.19 pmol/L, respectively. Mean serum fT3 and fT4 levels decreased significantly at 3rd and 6th months compared to baseline levels (p < 0.01 and p < 0.01, p < 0.01 and p = 0.001, respectively).

CONCLUSION

Systemic isotretinoin therapy causes significant alterations in sTFTs. Dose dependent or long-term effects of systemic isotretinoin on sTFTs needs further evaluation.

Presumed isotretinoin-induced extraocular myopathy

Isotretinoin a synthetic analogue of vitamin A is primarily used for cystic acne not responding to conventional treatment. Several ocular side effects including blurring of vision, decreased dark adaptation, corneal opacities and meibomian gland atrophy have been reported with prolonged use of isotretinoin. There have been reports of muscular damage caused by isotretinoin. Extra ocular myopathy as an adverse effect of long term used of isotretinoin has never been mentioned in literature. We report a case of a young male who presented to us with complaints of diplopia after using isotretinoin for a prolonged period. He was diagnosed as a case of presumed isotretinoin extraocular myopathy after imaging and other blood investigations.