Fatal toxic epidermal necrolysis associated with etretinate

Photodistributed Stevens-Johnson syndrome and toxic epidermal necrolysis: a systematic review and proposal for a new diagnostic classification

BACKGROUND

Ultraviolet radiation (UVR) exposure is commonly reported as a risk factor for Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, minimal evaluation of photo-induced SJS/TEN has been conducted. Thus, this review identifies all cases of SJS/TEN that are linked to an acute exposure of UVR and outlines the unifying characteristics of these cases. Furthermore, the theoretical pathogenesis, differential diagnoses, and proposed diagnostic criteria are defined.

METHODS

PubMed, Google Scholar, and other databases and websites were searched from inception to September 2021 to identify studies that met inclusion criteria. The following keywords were utilized: "Stevens-Johnson syndrome" and "toxic epidermal necrolysis" with "ultraviolet," "photodistributed," "photo-induced," "photosensitivity," and "photo." One reviewer assessed study characteristics, with confirmation by a second. The risk of bias was assessed independently by another.

RESULTS

Thirteen patient cases were identified, all reporting ultraviolet radiation prior to rash onset and an underlying causal drug. Case classifications included 7/13 SJS and 6/13 TEN. All cases described the rash as photodistributed with UVR exposure prior to rash onset (delay of 1-3 days) and a causal drug. 10 cases provided evidence that the photodistributed rash lacked linear demarcation (as in a sunburn) with satellite target-like lesions. No cases described a flu-like prodrome.

DISCUSSION

Mucositis, palmar and plantar rash, a positive Nikolsky sign, and a prolonged disease course can help distinguish from photosensitive reactions, while a negative direct immunofluorescence test is important to distinguish from other photo-induced disorders.

CONCLUSION

Physicians should be aware that UVR may precipitate SJS/TEN in patients taking susceptible drugs. After a 24-h delay from UVR exposure, a non-distinct, photodistributed rash appears with no flu-like prodrome and progresses for at least 48 h to include vesiculobullous eruptions and mucous membrane involvement. Photodistributed SJS/TEN appears to be photo-drug-induced with a unique onset and rash presentation that should be recognized as a distinct diagnosis.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN): could retinoids play a causative role?

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are overlapping manifestations on a spectrum of acute drug-induced conditions associated with severe blistering, skin peeling, and multi-organ damage. TEN is an eruption resembling severe scalding, with ≥30% skin detachment. SJS is a mild form of TEN, characterized histologically by epidermal keratinocyte apoptosis with dermo-epidermal separation and extensive small blisters with <10% body surface skin detachment. The syndrome can be induced by numerous medications and typically occurs 1–4 weeks after the initiation of therapy. Granulysin is found in the lesions of patients with SJS/TEN and plays a significant pathogenic role in the condition, but the overall mechanisms linking medications, granulysin, and disease manifestations remain obscure. This paper reviews evidence suggesting that the different medications implicated in SJS/TEN have the common property of interacting and synergizing with endogenous retinoids (vitamin A and its congeners), in many instances causing the latter to accumulate in and damage the liver, the main storage organ for vitamin A. It is hypothesized that liver damage leads to the spillage of toxic retinoid compounds into the circulation, resulting in an endogenous form of hypervitaminosis A and cytotoxicity with widespread apoptosis, mediated by granulysin and recognized as SJS/TEN. Subject to testing, the model suggests that symptom worsening could be arrested at onset by lowering the concentration of circulating retinoids and/or granulysin via phlebotomy or plasmapheresis or by pharmacological measures to limit their expression.

Isotretinoin therapy and depression – evidence for an association

Objectives: The object of this paper is to evaluate the evidence suggesting an association between the use of the anti-acne agent isotretinoin and the subsequent development of depression.

Method: Three case histories of individuals who had received treatment with isotretinoin and subsequently developed depression are reviewed.

Results: All three individuals were noted to have a depressive illness which was notable by the prominence of symptoms of irritability, agitation and aggression.

Conclusions: The indications from the three cases described suggest that there appears to be an association between depression and the recent use of isotretinoin. This may relate to the ability of isotretinoin to simulate hypovitaminosis A, with aggression, irritability and depression as a direct result of this effect. Young males may be particularly prone to developing this response.

Risk of melanoma with psoralen/ultraviolet A therapy for psoriasis. Do the known risks now outweigh the benefits?

Since the introduction in the 1970s of treatment with oral psoralens with longwave ultraviolet radiation in the A range (PUVA), there has been an increasing concern about the long term carcinogenic effect of the therapy. The main indication for PUVA is psoriasis, a common, chronic and intractable skin disease that affects 1 to 3% of the world's population. The effectiveness of PUVA in inducing and maintaining the remission of severe psoriasis has been amply documented. Although psoriasis is not a life-threatening disorder, it may be associated with restriction of activities and days lost to hospitalisation. Therefore, a number of systemic treatments such as methotrexate and cyclosporin have been used. None of these treatments has been as carefully studied for long term adverse effects as PUVA. The short-term adverse effects of PUVA are generally well known and tolerated. The major mid-term adverse effect, squamous cell carcinoma of the skin, has been well documented in a number of large-scale epidemiological studies that have led to recommendations such as to restrict the lifetime number of treatments. Although squamous cell carcinoma is potentially life-threatening, it is usually slow growing and can be adequately managed by proper surveillance, treatment and follow-up. The situation is quite different for malignant melanoma, which is often fast growing and fatal. Except for anecdotal reports, malignant melanoma has not been observed in PUVA patients until recently. However, a report of a cohort of 1380 patients with psoriasis has concluded that about 15 years after the first treatment the risk of melanoma is increased approximately 5-fold in patients treated with high doses. Although this report needs to be confirmed by other multicentre trials, it is alarming since the association between exposure to ultraviolet light and development of melanoma is well established both in humans and in experimental animals. Until this study is validated, it is recommended that the guidelines for PUVA therapy should be rigorously followed and that the contra-indications should be extended to include history or family history of melanoma and patients who have already received > 200 treatments.

Adverse reactions to oral retinoids. An update

Retinoids, both naturally occurring and synthetic, are analogues of vitamin A. They represent a major advance in the treatment of acne and psoriasis, as well as rarer conditions such as the ichthyoses. The more frequent and widespread use of these drugs requires that the dermatologist be aware of the wide spectrum of adverse events that may be encountered with their use. Some are serious and irreversible, such as teratogenicity, necessitating great care if these drugs are given to women of childbearing potential. Other effects may be less severe, dose dependent and reversible. Although not devastating to the patient, appropriate advice may reduce morbidity.

Side effects of systemic retinoids and their clinical management

The safety profile of oral retinoids appears to be well established, although rare new side effects are occasionally reported. Appropriate patient selection, use of the lowest required dose, and adequate follow-up are significant factors in the prevention of these toxicities. Teratogenicity, which can be avoided by following recommended precautions, is the main adverse effect.