Fixed drug eruption

What it is

From: Orphanet

A rare hypersensitivity reaction characterized by the appearance of erythematous or violaceous, round, sometimes painful, plaques that may or may not result in long-lasting pigmentation and which recur (usually at the same site) upon re-exposure to the causative medication. The severe form of the disease, generalized bullous fixed drug eruption, occurs typically in the elderly and may be life-threatening. Onset usually occurs 30 minutes to several hours after administration of the causal medication. Many medications, including paracetamol, have been implicated. The disease may rarely be induced by food. Histology is characterized by interface dermatitis or epidermal necrolysis in bullous forms.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Adverse drug response · Very frequent (99-80%)

An unpleasant or harmful reaction resulting from treatment with a drug.

Drug allergy · Very frequent (99-80%)

Hypersensitivity in form of an adverse immune reaction against drugs.

Erythema · Very frequent (99-80%)

Redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin.

Erythematous plaque · Frequent (79-30%)

A plaque (a solid, raised, plateau-like (flat-topped) lesion greater than 1 cm in diameter) with a red or reddish color often associated with inflammation or irritation.

Junctional split · Frequent (79-30%)

The formation of bullae (blisters) with cleavage in the lamina lucida layer of the skin.

Regional abnormality of skin · Frequent (79-30%)

An abnormality of the skin that is restricted to a particular body region.

Abnormal blistering of the skin · Occasional (29-5%)

The presence of one or more bullae on the skin, defined as fluid-filled blisters more than 5 mm in diameter with thin walls.

Fatigue · Occasional (29-5%)

A subjective feeling of tiredness characterized by a lack of energy and motivation.

Fever · Occasional (29-5%)

Body temperature elevated above the normal range.

Hyperpigmentation of the skin · Occasional (29-5%)

A darkening of the skin related to an increase in melanin production and deposition.

Oral ulcer · Occasional (29-5%)

Erosion of the mucous mebrane of the mouth with local excavation of the surface, resulting from the sloughing of inflammatory necrotic tissue.

Skin detachment · Occasional (29-5%)

Loss of sections of skin either spontaneously or after gentle handling.

Skin erosion · Occasional (29-5%)

A discontinuity of the skin exhibiting incomplete loss of the epidermis, a lesion that is moist, circumscribed, and usually depressed.

Stomatitis · Occasional (29-5%)

Stomatitis is an inflammation of the mucous membranes of any of the structures in the mouth.

Other findings in the same source

From: Orphanet

Additional reported features include Chills (Very rare (<4-1%)); Generalized abnormality of skin (Very rare (<4-1%)); Crusting erythematous dermatitis (Very rare (<4-1%)); Vaginal mucosal ulceration (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Frequency and the population described

From: Orphanet

Point prevalence: Unknown; Worldwide; Class only.

Which doctor should you see?

The suggested department for discussing Fixed drug eruption is Dermatology, with a dermatologist as the relevant type of clinician. Dermatologist; paediatric services for children as appropriate.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which features of the skin, hair or nails distinguish the possibilities?
• Would photographs over time help document the changes?
• What should be expected from treatment, and how will irritation or other adverse effects be managed?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Fixed drug eruption. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.