Sweet syndrome

What it is

From: Orphanet

A rare inflammatory disease characterized by abrupt appearance of painful, edematous and erythematous papules, plaques and nodules on the skin, and frequently accompanied by fever and neutrophilia with a dense infiltration of mature neutrophils that are typically located in the upper dermis. The disease is classically associated with inflammatory disease, pregnancy, infection (mostly of the upper respiratory tract), or vaccination but may be idiopathic, associated with a hematological or visceral malignancy, or drug-induced.

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.

Abnormal circulating interleukin concentration · Very frequent (99-80%)

The concentration of an interleukin (a class of cytokines) is outside the limits of normal.

Erythematous papule · Very frequent (99-80%)

A circumscribed, solid elevation of skin with no visible fluid that is reddish (erythematous) in color.

Erythematous plaque · Very frequent (99-80%)

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.

Pain · Very frequent (99-80%)

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Predominantly dermal neutrophilic infiltrate · Very frequent (99-80%)

Collection of neutrophils in the dermis.

Skin nodule · Very frequent (99-80%)

Morphologically similar to a papule, but greater than either 10mm in both width and depth, and most frequently centered in the dermis or subcutaneous fat.

Abnormality of the face · Frequent (79-30%)

An abnormality of the face.

Abnormality of the hand · Frequent (79-30%)

An abnormality affecting one or both hands.

Abnormality of the neck · Frequent (79-30%)

An abnormality of the neck.

Abnormality of tumor necrosis factor secretion · Frequent (79-30%)

An abnormality in the production or cellular release of tumor necrosis factor.

Acne · Frequent (79-30%)

A skin condition in which there is an increase in sebum secretion by the pilosebaceous apparatus associated with open comedones (blackheads), closed comedones (whiteheads), and pustular nodules (papules, pustules, and cysts).

Arthralgia · Frequent (79-30%)

Joint pain.

Elevated circulating C-reactive protein concentration · Frequent (79-30%)

The concentration of C-reactive protein in the blood circulation is above the upper limit of normal.

Elevated erythrocyte sedimentation rate · Frequent (79-30%)

An increased erythrocyte sedimentation rate (ESR). The ESR is a test that measures the distance that erythrocytes have fallen after one hour in a vertical column of anticoagulated blood under the influence of gravity. The ESR is a nonspecific finding. An elevation may indicate inflammation or may be caused by any condition that elevates fibrinogen.

Other findings in the same source

From: Orphanet

Additional reported features include Increased circulating interleukin 6 concentration (Frequent (79-30%)); Increased total leukocyte count (Frequent (79-30%)); Myalgia (Frequent (79-30%)); Myositis (Frequent (79-30%)); Neutrophilia (Frequent (79-30%)); Non-periodic recurrent fever (Frequent (79-30%)); Small vessel vasculitis (Frequent (79-30%)); Sterile abscess (Frequent (79-30%)); Abnormal blistering of the skin (Occasional (29-5%)); Abnormal drug response (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Adult

Inheritance in the source

From: Orphanet

Multigenic/multifactorial

Frequency and the population described

From: Orphanet

Point prevalence: Unknown; Worldwide; Class only.

Which doctor should you see?

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

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

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 Sweet syndrome. 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.