Keratoacanthomas (KA) are cutaneous tumors originating from the hair follicle. Generalised eruptive KA (GEKA) or Grzybowski syndrome is a rare variant of KA, characterised by an eruption of multiple intensely pruiritic dome-shaped papules with keratotic cores. Immunological abnormalities, excessive sunlight exposure, infection with Human Papillomavirus and trauma are proposed aetiologies. Treatment remains difficult, with varying results from topical, systemic and surgical therapies.
We describe a patient with severe GEKA, on a background of a new diagnosis of myelodysplastic syndrome (MDS). This is the third documented patient to have both MDS and multiple keratoacanthomas.
An 87-year-old male was referred with histopathological findings of GEKA on his right ear, following a sudden eruption of multiple keratotic papules over his scalp, neck, face and buccal mucosa. This was associated with a 10kg unintentional weight loss. He was found to have MDS and commenced on azacytidine therapy. Acitretin 10mg/day was trialed for 8 weeks but was ineffective, as was doxycycline 100mg daily for 2 weeks. Cryotherapy showed improvement in some lesions, and other lesions regressed spontaneously. Topical trichloroacetic acid, methylprednisolone and menthol 1% provided no relief. Improvement in his peripheral blood counts following 6 cycles of azacytidine was associated with significant improvement of his cutaneous lesions.
There may be an association between GEKA with immunological abnormalities including autoimmune disease, haematological malignancy or immunosuppression from medication. Upon review of other cases, is unclear whether the development of MDS and GEKA occur concurrently, or whether treatment for MDS is a risk factor for its occurrence. Some cases showed good responses to retinoid and topical treatments, however our patient had most significant improvement with treatment of his underlying MDS. More research is needed to determine aetiology and immunological pathways of this condition, in order to establish reliable therapies for a disease that carries significant morbidity.