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Table 1 Fortaleza classification

From: High-resolution infrared thermography: a new tool to assess tungiasis-associated inflammation of the skin

Stages   Symptom Parasite activity Time period
Penetration Stage I Erythema Penetration 3–7 h
Beginning hypertrophy Stage II Pruritus, pain, erythema around central dark dot Beginning hypertrophy Days 1–2 after penetration, lasting 2–3 days
White halo Stage IIIa White halo surrounding the black dot, faecal coils, egg expulsion Hypertrophy into a sphere Days 2–3 after penetration, lasting 3–4 days
Stage IIIb White halo, caldera formation, loss of firmness, faecal coils, egg expulsion Development of a rim surrounding the rear cone Days 6–7 after penetration, lasting 2 weeks
Involution Stage IVa No egg excretion, wrinkled lesion Shrinking hypertrophy, dying parasite 3–4 weeks after penetration, lasting 1–2 weeks
Stage IVb Necrotic, dissected lesion Dead parasite 4–6 weeks after penetration, lasting 1–2 weeks
Residuum Stage V Circular depression in the stratum corneum No parasite 6–7 weeks after penetration for several months or permanent