Sterile pustules in dermatology

1. Pyoderma gangrenosum

It causes chronic, recurrent, sterile pustular ulcers associated with inflammatory bowel disease. The pustular variant features discrete pustules surrounded by a halo, mainly on the lower limbs, trunk, and mucosa.

2. Sweet syndrome

Also known as acute febrile neutrophilic dermatosis, it presents with fever, erythematous plaques and raised neutrophil count. The pustular variant is rarer and linked to inflammatory bowel disease.

3. Behcet disease

It presents with recurrent oral and genital aphthae, pseudo-folliculitis with sterile pustules, erythema nodosum, and acneiform eruptions.

4. Subcorneal pustular dermatosis (Sneddon-Wilkinson Disease)

It causes sterile, flaccid pustules often in flexural areas. The hypopyon sign is characteristic [Figure 2].

Close

Figure 2:

A single pustule with the characteristic hypopyon signin subcorneal pustular dermatoses.

Export to PPT

6. Neutrophilic eccrine hidradenitis

It is seen commonly in patients receiving chemotherapy; presents as tender erythematous plaques studded with sterile pustules, often involving eccrine-rich areas.

1. Acute generalised exanthematous pustulosis (AGEP)

AGEP is a severe drug reaction that typically manifests with the rapid development of multiple, non-follicular, sterile, pinhead-sized pustules that usually occur a few hours to a few days after exposure to an offending drug, most often an antibiotic (eg, aminopenicillins, quinolones, pristinamycin, etc.) [Figure 3].

Close

Figure 3:

Multiple, discrete, pinpoint pustules on an erythematous base on upper back seen in a patient after taking tablet amoxicillin.

Export to PPT

2. Bowel-associated dermatitis-arthritis syndrome (BADAS)

BADAS is characterised by presence of sterile pustular vasculitis associated with blind loops of bowel or other causes of stasis of bowel contents. It is usually seen following jejunoileal bypass or gastric resection.²

3. Drug-induced

Prolonged intake of drugs like topical and systemic corticosteroids, along with certain other drugs [Table 1]¹ can result in pustular lesions with other cutaneous manifestations [Figure 4].

Close

Figure 4:

Numerous papules and pustules with crusting and serous discharge on face after application of topical betamethasone for 6 months.

Export to PPT

PRIDE COMPLEX: Papulopustulas and/or paronychia, regulatory abnormalities of hair growth, itching, and dryness due to Epidermal growth factor receptors (EGFR) inhibitors¹ [Figure 5].

Close

Figure 5:

Multiple papules and pustules on eyebrows after taking tablet erlotinib for lung carcinoma.

Export to PPT

4. Post-photodynamic therapy (PDT)

Topical photodynamic therapy has been used for a diverse range of conditions in dermatology. Acute and short-term effects of PDT are itch, pain, oedema, crusting, sterile pustules, infection, erosive pustular dermatosis, and bullous pemphigoid.³

1. Eosinophilic pustular folliculitis

Three clinical types have been described as follows:

• a)

  Classic eosinophilic pustular folliculitis (Ofuji disease) – It is most common in the Japanese population, characterised by chronic, recurrent follicular sterile pustules that tend to form a circinate pattern.

• b)

  Eosinophilic folliculitis of immunosuppression- It is most common in patients with HIV, characterised by papules and sterile pustules involving the face and upper trunk.

• c)

  Eosinophilic pustular folliculitis of infancy. It presents as annular clusters of follicular pustules on the scalp with associated eosinophilia.

2. Irritant contact dermatitis (ICD)

Irritant contact dermatitis is the cutaneous response to the physical or toxic effects of a wide range of environmental exposures. This may be an acute irritant contact dermatitis or a cumulative irritant dermatitis. ICD has a spectrum of clinical features, ranging from a little dryness to various types of eczematous dermatitis. The pustules, which as a part of this spectrum are usually sterile unless secondarily infected¹ [Figure 6a and 6b].

Close

Figure 6a:

Numerous pinhead sized papules and pustules in peri-nasal and peri-oral areas in a patient after playing with holi colours.

Export to PPT

Close

Figure 6b:

ICD-Close up view. (ICD: Irritant contact dermatitis).

Export to PPT

3. Erosive pustular dermatosis

It classically presents as sterile pustules, keratotic crusts, erosions, and mild inflammation arising within the atrophic, photodamaged skin of a bald scalp. It is one of the cutaneous manifestations of chronically photodamaged skin.⁴

4. Acute generalised pustular bacterid

It is a rare dermatosis presenting as sterile pustules on an erythematous base, commonly involving palms and soles, thought to be a reaction to an infectious focus elsewhere.⁵ These conditions must also be carefully differentiated from clinically similar infective pustular dermatoses. A list of commonly encountered sterile pustular conditions is provided in Table 2¹, while Table 3¹ offers an overview to aid in clinical evaluation and decision-making. Table 4 offers the overview of sterile pustules in dermatology.