What is Lamictal Rash?
Lamictal is one of the brand names for the drug Lamotrigine. It is a long-acting drug that was first synthesized to treat epileptic seizures. This drug belongs to a group of drugs called anticonvulsants. It is used for:
- Partial seizures, tonic-clonic seizures
- Lennox-Gastaut syndrome
- Maintenance and treatment of bipolar disorder
Some patients can develop a reaction to the drug, which presents as rash. In some cases the rash can be life-threatening and cause Steven-Johnson syndrome .
Causes of Lamictal rash
The exact cause of Lamictal rash is unknown. Some specialist believe that it is caused by administering too high of a dose when beginning the treatment. also, there is a higher chance to develop rash if Lamictal is used together with valproic acid.
Valproic acid interferes with excretion of Lamictal therefore there are higher blood serum levels of it. The rash is more commonly seen in pediatric patients rather than in adults. The incidence of the rash has been reported at variable rates. Some sources say it is seen in 5-10% cases, while other studies report it to be present in less than 1% cases .
Symptoms of Lamictal rash
The rash can vary in severity. If the rash occurs 5 to 10 days after beginning to use the drug, it is probably Lamictal related. In mild cases the rash presents with red, blotchy patches or hives in a certain area of the body or all over the body. The red spots are widely spaced and might be itchy. Usually the rash resolves in 10 to 14 days and is not accompanied by other symptoms that could possibly explain the rash.
Serious rash occurs less commonly. It is characterized by the involvement of mouth, tongue, face and genital/anal area. The rash is more prominent on the neck and upper trunk. Fever or flu like symptoms usually accompany the rash. Other symptoms include:
- Red or purple looking rash
- Tender to touch
- The rash merges and appears swollen
- Redness and swelling all over the body
- Hospitalization might be required
- Complete blood count, blood urea and creatinine levels and liver enzymes should be normal 
There are four main types of Lamictal rash:
- Hypersensitivity reaction- fixed eruptions, itchiness, exanthema, urticaria, edema
- Rash associated with mood stabilizers: photosensitivity, loss of body hair, increased pigmentation.
- Severe, life threatening conditions: Steven Johnson syndrome, toxic epidermal necrolysis, severe hypersensitivity reaction, exfoliative dermatitis.
- Exacerbation of existing skin condition: acne, psoriasis, seborrhea, hyperhidrosis .
Side effects of Lamictal
Besides the rash, Lamictal can also cause other side effects like:
- Double or blurred vision
- Insomnia or sleepiness
- Chest pain
- Peripheral edema
- Dermatitis, dry skin
- Increased libido
- Rectal hemorrhage
Management of Lamictal rash
Discontinuation of Lamictal
Therapy guidelines state that in case rash occurs after 5 to 10 days of initiating the treatment, use of Lamictal should be stopped, regardless of the type or severity of the rash. Initial dosing of Lamictal can play an important role in the possibility of rash. If the patient has had reaction to the drugs, the therapy should be introduced in very small dosages.
In patients who use valproic acid, Lamictal should be given in smaller dosages because of the increased risk of rash. Lamictal is metabolized by process called glucuronic acid conjugation therefore medications that induce or inhibit this process can cause variability in the half-life or Lamictal.
Usually the half-life of Lamictal is 24h. Use of carbamazepine, phenytoin, phenobarbital and estrogen-containing contraceptives shorten this time to around 14 hours. Valproic acid increases the half-live of Lamictal to around 70 hours. One of the biggest issues of Lamictal use, is that the exact therapeutic dosage is not known and it has to be administered based on the therapeutic response of every patient [3,5].
Usually if the rash is mild, it goes away after a time and doesn’t require any treatment. The rash should resolve within 10 to 14 days.
If the rash is severe, medical help should be sought. Usually the treatment includes using antihistamines and steroids. In severe cases, when the throat is closed up, intubation of the patient might be required.
In case of severe side effects, like toxic epidermal necrolysis, monitoring of fluid intake and urine output should be observed. Therapy usually requires electrolyte balance regulation with intravenous fluids. Also, loss of body temperature should be prevented and parenteral feeding has to be started. Extra precaution should be taken to prevent bacterial infection. In some cases prophylactic antibiotics are given [5,6].
- What is Lamictal rash: http://psycheducation.org/treatment/mood-stabilizers/the-big-three-for-bipolar-depression/lamotrigine-lamictal/details-on-the-lamotrigine-rash/
- General drug information: https://medlineplus.gov/druginfo/meds/a695007.html
- Symptoms, causes and management: https://academic.oup.com/ijnp/article/12/2/257/668826/Lamotrigine-associated-rash-to-rechallenge-or-not
- Symptoms and side effects: http://drugsdetails.com/lamictal-lamotrigine-rash/
- Treatment: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2658298/
- Treatment of toxic epidermal necrolysis: http://emedicine.medscape.com/article/229698-treatment?src=refgatesrc1#d11