What are the other Names for this Condition? (Also known as/Synonyms)

• Medication-Induced Pemphigus

What is Drug-Induced Pemphigus? (Definition/Background Information)

• Drug-Induced Pemphigus is a form of pemphigus, a skin disorder, which is triggered by medication use. The medications commonly responsible for the condition include penicillamine (most common offending drug), bucillamine, and ACE inhibitors 
• Pemphigus is a benign and chronic skin disorder commonly affecting mid-to-elderly adults. It is characterized by the formation of painful blisters on the surface of the skin and mucous membranes, and is caused by immune system dysregulation
• Stopping or discontinuing the use of such medications may decrease progression of Drug-Induced Pemphigus and/or may result in resolution of the condition. The prognosis on stoppage of the medication is excellent in a vast majority of cases

Who gets Drug-Induced Pemphigus? (Age and Sex Distribution)

• Drug-Induced Pemphigus may be observed in individuals of all age groups. However, a majority of cases are reported in adults over the age of 30 years
• Both males and females are affected
• Worldwide, the condition may affect individuals of all racial and ethnic groups

What are the Risk Factors for Drug-Induced Pemphigus? (Predisposing Factors)

The key risk factor for Drug-Induced Pemphigus is the use of certain medications (to treat other health conditions) that lead to the skin condition as an unintended side effect or complication. The medications implicated include:

• Thiol-based medications that include penicillamine and captopril
• Antibiotics such as cephalosporin, penicillin, and vancomycin
• Antihypertensives including ACE inhibitors
• Non-steroidal anti-inflammatory drug (NSAID) such as piroxicam

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Drug-Induced Pemphigus? (Etiology)

Drug-Induced Pemphigus develops from the use of certain medications/drugs that are administered for various health conditions. 

• It is believed that the offending drug potentially causes an abnormal cell-mediated immune response in the body 
• The onset of the condition is usually slow, typically taking several weeks to months before first onset of skin symptoms

In general, pemphigus is described as an autoimmune (blistering) disorder of skin in which an individual's immune system attacks their own skin components, due to the production of immunoglobulin antibodies. This results in the characteristic signs and symptoms of the disorder.

What are the Signs and Symptoms of Drug-Induced Pemphigus?

The signs and symptoms of Drug-Induced Pemphigus may vary from one individual to another. It may also be mild or severe and may be related to the type and usage of the drug. The symptoms may vary depending on the type of pemphigus one is affected with, such as pemphigus vulgaris or pemphigus foliaceus, etc.

In general, the signs and symptoms may include:

• Presence of small fluid-filled blisters on skin; the blisters involve the superficial skin layers
• The blisters may rupture or extend when rubbed, called the Nikolsky's sign
• Following rupture and discharge of fluid, the sores erode with the formation of crusts and scaly skin
• The condition may progress over many weeks, affecting the entire body surface
• There may be painful blisters and erosions in the mouth and mucous membrane of the genitals

Pain, burning sensation, irritation, and itchiness are generally noted.

How is Drug-Induced Pemphigus Diagnosed?

The diagnosis of Drug-Induced Pemphigus may be difficult and challenging due to the following factors:

• Use of more than one type of medication for other health conditions
• Time period between use of the medication and onset of initial symptoms (which is known to take several months)

A diagnosis may involve the following exams and procedures:

• Physical examination of the individual and medical history evaluation (including evaluating current and past medication use)
• Nikolsky sign: The physician may rub the skin near the blister to check if the skin peels off. If it does, it is a possible sign of pemphigus
• Blood tests: Blood tests are conducted to check the level of desmoglein antibodies in blood. An elevated level of this antibody can help confirm the presence of pemphigus
• Blood tests, analysis of pus, and culture of the fluid being drained to check for any infections, if needed
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Direct and indirect immunofluorescence studies on the skin biopsy specimen

A differential diagnosis may be necessary to eliminate other conditions that present similar signs and symptoms.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Drug-Induced Pemphigus?

The possible complications due to Drug-Induced Pemphigus include:

• Emotional stress due to cosmetic issues
• Superimposed bacterial and fungal skin infections
• Oral cavity lesions causing severe eating difficulties
• Recurrence of the condition
• Treatment complications and medication side effects

How is Drug-Induced Pemphigus Treated?

Discontinuation of the causative medication may result in a cure or improvement of Drug-Induced Pemphigus.

If necessary, based on the healthcare provider’s evaluation, symptomatic treatment may be undertaken via the following measures:

• Topical and systemic corticosteroids are the mainstay of therapy
• If necessary, systemic immunosuppressant medications may be prescribed for severe cases
• Undertaking treatment of any secondary infections through administration of antibiotic or antifungal agents
• Good skin care and general body hygiene is important

Regular follow up visits with the healthcare provider is important and recommended.

How can Drug-Induced Pemphigus be Prevented?

Current medical research has not established a method of preventing Drug-Induced Pemphigus. However, the following measures may be considered to help lower one’s risk for the condition:

• Drugs that cause the condition may be discontinued or alternative medication prescribed; nevertheless, this has to be decided by the healthcare expert
• Avoid self-medication or bringing about any changes to one’s medication dosage without consulting the healthcare provider
• Inform your physician if you are allergic to any medication

What is the Prognosis of Drug-Induced Pemphigus? (Outcomes/Resolutions)

The prognosis of Drug-Induced Pemphigus is usually good in many cases, upon discontinuation of the medication and adequate treatment of the condition, as needed.

Additional and Relevant Useful Information for Drug-Induced Pemphigus:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/