Acrodermatitis Continua


  • A variant of pustular psoriasis that has a persistent, relapsing course. Classified as a noninfectious neutrophilic dermatosis; acropustular eruption with a predilection for distal digits characterized by sterile pustules; early nail involvement
  • Synonym(s): acrodermatitis continua of Hallopeau; acrodermatitis perstans; dermatitis repens; pustular acrodermatitis


  • Acute manifestations
    • Formation of multiple, sterile, painful pustules that have an erythematous base located surrounding and under the nail(s) that coalesce to form polycyclic “lakes of pus,” which subsequently rupture and crust
  • Chronic sequelae
    • Nail changes: paronychia, onychodystrophy, onycholysis, onychomadesis, and anonychia
    • Scaling of the nail bed and periungual skin
    • Sclerosis or atrophy of soft tissue adjacent and deep to nail bed
    • Osteolysis of underlying bone, particularly distal phalanges
  • Distribution
    • Typically affect distal extremities, affecting 1 to 2 digits, most frequently the 1st digits of the hands; can involve all fingers and toes
    • Predilection for dorsal surfaces of hands and feet
    • Spare the central palmar/plantar regions
    • Rarely spread proximally to involve feet, ankles, hands, and forearms. Isolated proximal psoriatic plaques are rare.


  • Exceedingly rare: Only case studies and series are available.
  • Female predominance
  • Predominantly in adults but also seen in children: observed in 4.7% cases of infantile psoriasis in one series

Etiology and Pathophysiology

  • Immune dysregulation: Acute-phase reactants such as IL-1 and IL-36 likely play a role in pathogenesis (1).
  • In some instances, digital trauma or infection may be an inciting event.


  • Reported associations with mutations in the IL36RN gene, which codes for the IL-36 receptor antagonist and is a cause of familial generalized pustular psoriasis (1,2)
  • No observed relationship with plaque psoriasis–associated alleles HLA-B13, HLA-B17, or HLA-BW37

Risk Factors

  • History of psoriasis, particularly pustular variant
  • Digital trauma
  • Local infection
  • Smoking may contribute to exacerbations.


  • Defined by clinical evolution and histopathologic features
  • Frequently missed, often a diagnosis of exclusion


  • Onset, including any triggering event
  • Duration of eruption, previous episodes
  • Local trauma or infection
  • Impairment in manual dexterity or ambulation
  • Localized symptoms: pain, pruritus, arthritis
  • Systemic symptoms: fever, malaise, weight loss
  • History of other immune disorder such as psoriasis, arthritis, or celiac disease
  • Smoking history

Physical Exam

  • Examine all skin surfaces, nails, scalp, and mucous membranes.
  • Examine joints, evaluating for swelling, erythema, or effusion.
  • Palpate axillary, epitrochlear, and inguinal lymph nodes to assess for lymphadenopathy.
  • Observe and evaluate gait and manual dexterity.
  • Measure vital signs.

Differential Diagnosis

  • Bacterial infection, especially staphylococcal
  • Herpetic whitlow
  • Cutaneous candidiasis
  • Allergic contact dermatitis
  • Dyshidrotic eczema
  • Parakeratosis pustulosa (in children)
  • Pemphigus vulgaris
  • Squamous cell carcinoma, particularly in advanced disease

Diagnostic Tests & Interpretation

Initial Tests (lab, imaging)

  • Aspiration of fluid from pustules. The following should be performed on fluid:
    • Gram stain smear
    • Potassium hydroxide preparation
    • In vitro culture
  • Cultures are typically sterile, unless secondary infection is present.
  • There are no characteristic serologic findings; however, acute systemic inflammation during flares may result in
    • Increased neutrophil count
    • Increased C-reactive protein
  • X-rays of hands and feet may show acroosteolysis, especially in long-standing disease. Ankle osteolysis may also be observed and is usually unilateral.

Follow-Up Tests & Special Considerations
Additional laboratory tests may be necessary to monitor for side effects of treatment.

Diagnostic Procedures/Other
Full-thickness cutaneous punch biopsy of an active pustule may establish diagnosis and should be performed (3,4).

Test Interpretation

  • Nail bed epithelium and adjacent epidermis
    • Compact hyperkeratosis with parakeratosis with or without neutrophils
    • Focal, subcorneal neutrophilic aggregates
    • Spongiform pustules of Kogoj (leukocyte aggregates between epidermal cells, associated with spongiosis)
    • Psoriasiform epidermal hyperplasia
    • Hemorrhagic foci displaying erythrocytes and hemosiderin
  • Dermis
    • Superficial perivascular inflammatory infiltrate composed of lymphocytes, histiocytes, and neutrophils
    • Tortuous, dilated vessels displaying erythrocyte extravasation
    • Edema of papillary dermis


  • Due to the rarity of this disease, only expert opinion and case reports are available to guide treatment recommendations.
  • Notoriously refractory to treatment, including topical and systemic agents used successfully in psoriasis
  • The agents listed below may be more effective when used in combination than as monotherapy.
  • Repeated courses or prolonged treatment is often necessary.


  • Topicals
    • Application under occlusion enhances absorption.
    • Topical agents generally have favorable side effect profiles but may be ineffective, especially as monotherapy:
      • Vitamin D3 analogs, such as calcipotriol: alone or combined with topical tacrolimus, betamethasone dipropionate, or oral acitretin (4)
      • Topical corticosteroids, with or without occlusion
      • May be combined with an oral antibiotic such as a tetracycline (4)
    • 5-Fluorouracil (4)
    • Tacrolimus ointment, with or without occlusion (4)
    • Anthralin (3)
  • Systemics
    • Systemic medications are generally more effective than topicals, although may be more expensive and carry increased risk of adverse effects.
    • Tumor necrosis factor-α (TNF-α) inhibitors
      • Adalimumab has shown greatest effectiveness at 40 mg every 1 to 2 weeks (3,4).
      • Etanercept 20 to 50 mg twice per week (4)
      • Infliximab 5 mg/kg IV at 0, 2, and 6 weeks and then at 8-week intervals (4)
      • Ustekinumab (5)
      • Sometimes combined with oral acitretin, methotrexate, cyclosporine, or prednisone
    • Cyclosporine (4)
    • Acitretin: possible synergistic effect with topical calcipotriol (4)
    • If cultures show secondary infection, treat with appropriate antibiotics:
      • Sulfones, namely dapsone
      • Tetracyclines
    • Colchicine

Additional Therapies

  • Phototherapy and photochemotherapy have been successful as monotherapies or in conjunction with medications.
  • Targeted narrow-band ultraviolet B phototherapy
    • As monotherapy or in conjunction with systemic medications (4)
  • Psoralen ultraviolet A
    • With selective hand bath psoralen (4)
  • Low-level polarized polychromatic noncoherent light (LPPL) plus 0.1% methylprednisolone aceponate cream

Issues For Referral

If there is suspicion of psoriatic arthritis, refer to a rheumatologist.

Ongoing Care

Follow-up Recommendations

Long-term management by a dermatologist


  • Generally persistent, chronically relapsing course
  • May lead to severe disability or complications warranting hospitalization


  • Association with or progression to PPP or GPP
  • Psoriatic arthritis (possible association)
  • Significant psychosocial impact, due to pain and resultant loss of manual dexterity
  • Fever and systemic inflammatory response syndrome
  • Treatment-related complications, depending on agent used



  • L40.2 Acrodermatitis continua


  • 696.1 Other psoriasis


  • 200976008 Acrodermatitis continua (disorder)
  • 58143000 Localized acrodermatitis continua of Hallopeau (disorder)
  • 83839005 Acrodermatitis continua of Hallopeau

Clinical Pearls

  • Rare variant of pustular psoriasis that preferentially affects the fingers and toes, often leading to significant pain and loss of function
  • Diagnosis typically made by punch biopsy is classically refractory to treatment, although case reports show that a variety of agents may have limited efficacy. Adalimumab may be the most promising option.


Amulya D. Amirneni, MD


  1. Sugiura K. The genetic background of generalized pustular psoriasis: IL36RN mutations and CARD14 gain-of-function variants. J Dermatol Sci. 2014;74(3):187–192. [PMID:24656634]
  2. Abbas O, Itani S, Ghosn S, et al. Acrodermatitis continua of Hallopeau is a clinical phenotype of DITRA: evidence that it is a variant of pustular psoriasis. Dermatology. 2013;226(1):28–31. [PMID:23428889]
  3. Razera F, Olm GS, Bonamigo RR. Neutrophilic dermatoses: part II. An Bras Dermatol. 2011;86(2):195–211. [PMID:21603801]
  4. Sehgal VN, Verma P, Sharma S, et al. Acrodermatitis continua of Hallopeau: evolution of treatment options. Int J Dermatol. 2011;50(10):1195–1211. [PMID:21950286]
  5. Di Costanzo L, Napolitano M, Patruno C, et al. Acrodermatitis continua of Hallopeau (ACH): two cases successfully treated with adalimumab. J Dermatolog Treat. 2014;25(6):489–494. [PMID:24215490]

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