Dermatoscope for the diagnosis of erythema with purpura induced by lidocaine/prilocaine cream: A case report

Abstract

BACKGROUND

Lidocaine/prilocaine (EMLA) cream is a local anesthetic that is applied to the skin or mucosa during painful therapeutic procedures with few reported side effects.

CASE SUMMARY

Here, we report the use of dermatoscopy to identify a case of erythema with purpura, a rare side effect, after the application of 5% EMLA cream.

CONCLUSION

We conclude that erythema with purpura is caused by irritation and toxicity associated with EMLA, but the specific mechanism by which the toxic substance affects skin blood vessels is unclear. In response to this situation and for cosmetic needs, we recommend tranexamic acid, in addition to routine therapy, to prevent changes in pigmentation in patients with dermatitis.

Key Words: Erythema, Purpura, Lidocaine/prilocaine, Dermatoscope, Toxic reaction, Case report

Core Tip: We report erythema and purpura under dermatoscope induced by lidocaine/prilocaine (EMLA) in a female in the process of cosmetic dermatology. We analyzed the possible etiology and pathology of the dermatitis specifically. This is the first time to share this case report, of which the content has not been published, nor has submitted for publication elsewhere. We expect this report will draw more attention to the use of EMLA especially from dermatologist for cosmetic therapy.

INTRODUCTION

5% lidocaine/prilocaine (EMLA) is a 1:1 low eutectic compound mixture of lidocaine and prilocaine. EMLA is a local anesthetic that is applied to the skin or mucosa during painful therapeutic procedures, such as foreskin surgery, cryosurgery of verrucae, vaccinations, medical cosmetic treatment and so on. EMLA use has been proven to be safe, without interactions associated with laser treatments or other cosmetic procedures[1]. Thus far, some mild adverse reactions have been reported, including erythema, blister, urticaria, allergic contact dermatitis, irritating contact dermatitis and pigmentation[2]. Serious adverse reactions may be life-threatening due to methemoglobinemia[3]. Here, we report a case of skin erythema with purpura, a rare side effect, after the application of 5% EMLA cream.

CASE PRESENTATION

Chief complaints

A 27-year-old female came to our department for facial cosmetic treatment. Large, scattered, edematous papules were found on the face, accompanied by burning and tingling sensations.

History of present illness

Our doctor planned to provide mesoderm therapy. Before the treatment, 5% EMLA (Tongfang Pharmaceutical Group Co., Ltd. Batch No. 210803) was evenly applied on the whole face (150 mg/cm²) and then covered with fresh-keeping film.

History of past illness

The patient did not have any obvious skin diseases, nor a history of chronic or infectious diseases, or drug allergies.

Personal and family history

The patient had no history of allergy to EMLA cream and did not report previous use of any type of non-steroidal anti-inflammatory drugs (NSAIDs). She visited our department many times to receive cosmetic treatments and did not have any abnormalities under local anesthesia with 5% EMLA.

Physical examination

After 20 minutes, large, scattered, edematous papules were found on the face, accompanied by burning and tingling sensations. Although the symptoms disappeared, there were some scattered, erythematous purpuric eruptions that remained (Figure 1A).

Figure 1 Skin changes induced by lidocaine/prilocaine cream. A: Erythematous purpuric macular lesion after application of 5% lidocaine/prilocaine cream; B: The arrow marks the petechial and purpuric lesion under dermatoscopy; C: Pigmental blot after purpuric eruption.

Laboratory examinations

The patient’s routine blood test result was normal.

Imaging examinations

Dermatoscope examination found that the skin lesion was filled with a purple background, vascular congestion was presented as a reticular structure, and dense purpuric globules were spreading (Figure 1B).

FINAL DIAGNOSIS

The patient received a diagnosis of dermatitis with purpura.

TREATMENT

Our doctor immediately removed the EMLA cream and treated her with yellow light for 10 minutes, then the mask was refrigerated for 30 minutes. Medical treatments included prednisone 15 mg qd (every day), Cetirizine 10 mg qn (every night), Vitamin C tablets 0.1 tid (three times a day), and Ello soft paste for the local lesions.

OUTCOME AND FOLLOW-UP

After 10 days, erythematous purpura subsided, and light pigmentation remained locally (Figure 1C).

DISCUSSION

Only a few cases of erythema with purpura induced by 5% EMLA cream, a rare side effect, have been reported[4-7]. We concluded that most of the reported adverse events occurred in infants. Some authors considered that there was an increase in capillary fragility in young children, as they were prone to severe vomiting, coughing or crying during treatment[6]. Van der Spek et al[7] suspected that the skin lesion was a toxic drug reaction of drugs, to some extent, but they did not further elaborate the toxic process.

However, in contrast to previous reports, we reported a rare case of erythema with purpuric lesions after the application of 5% EMLA cream in a 27-year-old female. The patient had no history of allergy to EMLA cream and did not report previous use of any type of NSAID. However, erythema with purpura appeared on the face 20 minutes after 5% EMLA cream (150 g/cm²) was applied. Dermatoscope examination revealed lesions with a purplish background, a network of congested vessels, and dense, enlarged purpura globules. The patient’s coagulation function was normal, and the drug patch test was negative. Although the patient was not considered to have an allergy to EMLA cream, the toxicity associated with EMLA cream was obvious.

EMLA (5%) is a 1:1 hypoeutectic compound mixture of lidocaine and prilocaine. In addition, an important excipient in the drug is castor oil, which is extracted from castor seeds and contains poisonous ricinine. We suspect that the castor oil excipient in the EMLA cream causes irritation and toxicity, and results in an erythematous purpuric rash. Although it has been documented that 5% EMLA has no damaging effect on skin microcirculation[7], we still believe that, according to dermoscopic manifestations, the toxic substance in EMLA acts directly on skin blood vessels. Although the exact mechanism is unclear, it has led to skin erythema with purpura. In addition, excessive EMLA application, application over a large area, long-term use, use in premature and term babies and patients with dermatitis, and the concomitant use of methemoglobin inducers may be the factors that cause toxic reactions associated with EMLA cream[8].

The purpuric eruption often vanishes in approximately two weeks, but in this case, the purpura caused mild pigmentation that lasted for a month. We have been treating another patient with EMLA-induced acute contact dermatitis, and her skin lesion was treated with topical Tranexamic acid, without any changes to pigmentation. Although in this case, the patient refused to take tranexamic acid due to personal reasons, tranexamic acid has been proven to be an effective and safe option for the prevention and treatment of skin pigmentation changes.

In conclusion, we should be aware of the risk of purpura caused by 5% EMLA cream, especially in cosmetic treatments. We recommend the use of tranexamic acid for the prevention and treatment of changes in pigmentation in patients with dermatitis as a result of 5% EMLA cream.

CONCLUSION

Regarding the routine use of EMLA as a local anesthetic for cosmetic treatment, we should ask about the patient’s allergy history and focus on the dosage, area of application and time of use. Most importantly, we should focus on skin reactions during external application. Petechial and purpuric lesions are rare reactions, and the pathogenesis of these adverse drug reactions remains unclear, but the main cause of irritation and toxicity caused by EMLA cream may be the drug’s ability to act on blood vessels. We recommend tranexamic acid, in addition to routine therapy, to prevent changes in pigmentation in patients with dermatitis.